Hexblade gone Insidious

[Kethrian]

      This time around, I wanted to rewrite the hexblade.  The suggested changes from Mike Mearls were a good start and brought the class more in line with paladin or ranger.  But since I've rewritten both of those to bring them up close to Bo9S levels, the hexblade needed a boost to catch it up.
   I tried some different things than most of my other martial rewrites this time around.  The hexblade is more about debuffing, so I expanded upon that by adding new abilities like that.  The Dark Companion ACF is often considered far superior to having a familiar, and so I figured it should just be a core change (as some other hexblade rewrites I've looked at have also done), but here it also improves as you gain levels now.
   Since I really believe in letting martial classes have a way of getting full attacks and still being able to move more than 5 feet, I created Dire Draw, where instead of the martial character moving and full attacking, the hexblade moves the target to him and delivers the full attack!  Or use it to save an ally, if you're feeling magnanimous.
   I also added or modified a few hexblade abilities to be stronger against casters, making a hexblade a potentially serious threat to all casters even without feats like Mage Slayer.
   While my paladin and ranger rewrites did not change their spell lists at all due to being core classes, the hexblade is ignored by many books, especially the PHB2 and SC, so I added spells to the list from both of those books.
   Finally, since the original hexblade gets a bunch of spells to hide or disguise itself, I modified several abilities to synergize with that, as well as adding hide and move silently to the class skill list.
   Comments and critiques are appreciated!


Hexblade

Alignment: Any Non-Good

Hit Die: d10

Table:

			Saves				Spellcasting
Lv	Base Attack Bonus	Fort	Ref	Will	Class Abilities	1st	2nd	3rd	4th
1	+1	+2	+0	+2	Hexblade's Curse, Necromantic Resistance	-	-	-	-
2	+2	+3	+0	+3	Magic Resistance, Cantrips	-	-	-	-
3	+3	+3	+1	+3	Mettle, Bonus Feat	-	-	-	-
4	+4	+4	+1	+4	Dark Companion	1	-	-	-
5	+5	+4	+1	+4	Combat Casting, Shadow Sight	1	-	-	-
6	+6/+1	+5	+2	+5	Dire Draw	2	-	-	-
7	+7/+2	+5	+2	+5	Improved Hexblade's Curse, Bonus Feat	2	1	-	-
8	+8/+3	+6	+2	+6	Aura of Unluck, Quick Cast 1/day	3	1	-	-
9	+9/+4	+6	+3	+6	Bestow Curse 1/day, Greater Shadow Sight	3	2	-	-
10	+10/+5	+7	+3	+7	Insidious Curse, Greater Dark Companion	4	2	1	-
11	+11/+6/+1	+7	+3	+7	Curse Eater, Quick Cast 2/day, Bonus Feat	4	3	1	-
12	+12/+7/+2	+8	+4	+8	Spell Resistance	5	3	2	-
13	+13/+8/+3	+8	+4	+8	Greater Hexblade's Curse, Greater Aura of Unluck	5	4	2	1
14	+14/+9/+4	+9	+4	+9	Bestow Curse 2/day, Quick Cast 3/day	5	4	3	1
15	+15/+10/+5	+9	+5	+9	Insidious Aura, Bonus Feat	5	5	3	2
16	+16/+11/+6/+1	+10	+5	+10	Dire Dark Companion, Superior Shadow Sight	6	5	4	2
17	+17/+12/+7/+2	+10	+5	+10	Heart of Darkness, Greater Bestow Curse, Quick Cast 4/day	6	5	4	3
18	+18/+13/+8/+3	+11	+6	+11	Dire Aura of Unluck	6	5	5	3
19	+19/+14/+9/+4	+11	+6	+11	Dire Hexblade's Curse, Bestow Curse 3/day, Bonus Feat	6	6	5	4
20	+20/+15/+10/+5	+12	+6	+12	Paragon of Misfortune, Quick Cast 5/day	7	6	5	4

Class Skills (4+int mod skill points per level, x4 at 1st level) Bluff (Cha), Climb (Str), Concentration (Con), Craft (Int), Diplomacy (Cha), Hide (Dex), Intimidate (Cha), Jump (Str), Knowledge (Arcana) (Int), Knowledge (Dungeoneering) (Int), Knowledge (Local) (Int), Listen (Wis), Move Silently (Dex), Profession (Wis), Ride (Dex), Sleight of Hand (Dex),  Spellcraft (Int), Spot (Wis), Swim (Str), Use Magic Device, and Use Rope (Dex).

Weapon and Armour Proficiencies: A hexblade is proficient with all simple and martial weapons, with light and medium armour, and with shields, except tower shields.  Hexblades do not suffer from arcane spell failure with light or medium armour, or with shields other than tower shields.

Hexblade's Curse (Su): The core of a hexblade's abilities is his ability to curse others.  As a swift action that does not provoke attacks of opportunity, he can place a curse on a creature within close range (25 feet + 5 feet per 2 levels).  The target must succeed on a Will save, DC 10 + ½ the hexblade's class level + his Charisma modifier, or suffer the curse, which inflicts a -3 circumstance penalty on attacks, saves, ability checks, skill checks, and weapon damage, and inflicts a 15% spell failure chance on all spellcasting and spell-like abilities for 1 minute.  The hexblade can have an active Hexblade's Curse on a number of targets equal to his Charisma bonus (minimum 1) simultaneously.  If he should successfully place a new curse on a new target, the oldest one ends immediately.  Hexblade's Curse is usable at will, but no more than once per round.
   Any effect which removes or dispels a curse works on Hexblade's Curse.
   Using Hexblade's Curse is not obvious.  The hexblade needs to merely crook a finger or the like and subtly point at his intended target in order to unleash the curse, and the curse manifests itself as simply bad luck, making it very hard to detect as anything out of the ordinary.  An alert observer suspicious of nefarious activities could attempt a Spot check opposed by the hexblade's Sleight of Hand check in order to notice the gesture.  A Knowledge (Arcana) check, DC 10 + the hexblade's level, is required to identify a Hexblade's Curse when it is in effect.  Also, uniquely, Hexblade's Curse does not trigger effects tied to "attacks", such as Invisibility.  An invisible hexblade can deliver his Hexblade's Curse and remain invisible, and any spell or effect which would trigger when an attack is made will not be set off by it.
   Of course, sometimes a hexblade wishes to draw attention, and so he can make a grand showing when he uses his Hexblade's Curse, in which case all who can see and hear him clearly know when the Hexblade's Curse is used, and who the target is.  In this instance, the "not an attack" feature of the Hexblade's Curse is waived, and any resulting effects are triggered as normal for placing a debilitating effect on another.

Necromantic Resistance (Su): A hexblade's training in the dark arts imbues him with a resistance to their destructive energies.  Hexblades have a resistance to negative energy equal to their class level.  If the hexblade is undead, however, he instead gains resistance to positive energy equal to his class level, as the dark arts instead infuse and shield him.

Magic Resistance (Su): At 2nd level, a hexblade gains a bonus equal to his Charisma bonus (minimum +1), up to a maximum equal to his hexblade level, on all saving throws against spells, spell-like abilities, and supernatural abilities.

Cantrips (Sp): A hexblade of 2nd level gets some cantrips that he can cast as spell-like abilities at will.  He picks 6 from the following list that he knows and can use, and can take another one every 3 levels after 2nd (5, 8, 11, 14, 17, and 20).  All hexblade spell-like abilities use his hexblade level as his caster level, and his Charisma determines their save DCs, as normal.
   Amanuensis, Arcane Mark, Caltrops, Daze, Dancing Lights, Detect Magic, Ghost Sound, Launch Bolt, Launch Item, Light, Mage Hand, Mending, Message, Open/Close, Prestidigitation, Ray of Frost, Read Magic, Silent Portal, Stick, Touch of Fatigue.

Mettle (Ex): Hexblades can resist certain attacks with greater effectiveness than others.  Beginning at 3rd level, a hexblade can shrug off effects that would hinder even the toughest warrior. If he succeeds on a Fortitude or Will save against an attack that would normally produce a lesser effect on a successful save (such as a spell with a saving throw entry of Will half or Fortitude partial), he instead negates the effect. The hexblade does not gain the benefit of mettle while unconscious.

Bonus Feat: At 3rd level and every 4 levels thereafter (7, 11, 15, and 19), a hexblade gains a bonus feat from the following list.  He must still meet any prerequisites required in order to take the feat desired.
   Ability Focus, Arcane Strike, Battle Caster, Blind Fight, Close-Quarters Fighting, Combat Reflexes, Deft Hands, Dodge, Mobility, Spring Attack, Bounding Assault, Rapid Blitz, Eschew Materials, Extra Slot, Extra Spell, Great Fortitude, Improved Critical, Improved Initiative, Iron Will, Lightning Reflexes, Magical Aptitude, Power Attack, Cleave, Great Cleave, Improved Sunder, Quick Draw, Shielded Casting, Somatic Weaponry, Spell Focus, Greater Spell Focus, Spell Penetration, Greater Spell Penetration, Weapon Finesse.

Dark Companion (Su): At 4th level, a hexblade can create a quasi-illusory companion, spun seemingly from the darkness of the night.  The companion's appearance is determined when it is first created, most commonly looking like a panther made of shadows, though other forms are possible, so long as it is either small or medium size.  The appearance ultmately has no effect on how the dark companion functions, however.  Creating the dark companion requires a ritual which takes 24 hours and uses up magic materials that cost 100 gp.  Once created, the dark companion stands with its master in battle, hindering his enemies' defenses.  The companion can be dismissed as a move action, or summoned as a free action.
   Any enemy adjacent to or sharing the space of a dark companion takes a -2 penalty on its saves and to its AC.  This penalty stacks with any other conferred by the hexblade, such as his Hexblade's Curse.  The companion's speed is equal to the hexblade's (including all modes of movement he possesses) and it acts during the hexblade's turn each round.  It follows his mental commands perfectly and without requiring an action from the hexblade - in effect, it is merely an extension of his will.
   The dark companion has no real substance, and thus cannot attack or otherwise affect creatures or objects.  It occupies a 5 foot space, even though it is insubstantial and can share its space with any creature.  It is immune to any damage or other effects that might harm creatures, though it can be dispelled or suppressed just like a spell effect.  The dark companion is treated as a spell whose level is equal to ½ the hexblade's class level.  If it is dispelled, it becomes unavailable for as long as a magic item would be suppressed.  If the dark companion ends up inside an anti-magic field or similar effect, the hexblade can resummon it outside the area, if possible.
   A dark companion cannot create flanking situations, nor does it provoke attacks of opportunity from movement, because enemies automatically recognize its insubstantiability.  If it is more than 120 feet from the hexblade at the start of his turn, or if he ever loses line of effect to it, it instantly reappears adjacent to him.  The dark companion has no real senses of its own, and cannot be used as a scout.

Spells: Beginning at 4th level, a hexblade gains the ability to cast a small number of arcane spells, which are drawn from the hexblade spell list.  He can cast any spell he knows without preparing it ahead of time, just as a sorcerer can.  To learn or cast a spell, a hexblade must have a Charisma score equal to at least 10 + the spell level (Cha 11 for 1st-level spells, Cha 12 for 2nd-level spells, and so forth).  The DC for a saving throw against a hexblade's spell is 10 + the spell level + the hexblade's Charisma modifier.
   Like other spellcasters, a hexblade can cast only a certain number of spells of each spell level per day.  His base daily spell allotment is given on the table above.  In addition, he receives bonus spells per day if he has a high Charisma score.
   The hexblade's selection of spells is extremely limited.  A hexblade begins play knowing no spells, but gains one or more new spells at certain levels, as indicated on the Spells Known table, below.  (Unlike spells per day, his Charisma score does not affect the number of spells a hexblade knows; the numbers on the table are fixed.)
   Upon reaching 7th level, and at every third hexblade level after that (10th, 13th, 16th, and 19th), a hexblade can choose to learn a new spell in place of one he already knows.  In effect, the hexblade "loses" the old spell in exchange for the new one.  The new spell's level must be the same as that of the spell being exchanged, and it must be at least one level lower than the highest-level hexblade spell the hexblade can cast.  For instance, upon reaching 10th level, a hexblade could trade in a single 1st or 2nd level spell (one spell level below the highest-level hexblade spell he can cast, which is 3rd) for a different spell of the same level.  A hexblade may swap only a single spell at any given level, and must choose whether or not to swap the spell at the same time that he gains new spells known for the level.
   Unlike most other arcane casters, a hexblade does not suffer from arcane spell failure from casting in light or medium armour, or when using a shield other than a tower shield.  He does, however, suffer the standard chance for any other type of armour or shield.
   After 1st level, a hexblade's caster level is equal to his hexblade level.  At 1st, he has no spells or spell-like abilities, and therefore has no caster level.

Spells Known
Level	1st	2nd	3rd	4th
1st	-	-	-	-
2nd	-	-	-	-
3rd	-	-	-	-
4th	2	-	-	-
5th	2	-	-	-
6th	3	-	-	-
7th	3	2	-	-
8th	4	2	-	-
9th	4	3	-	-
10th	5	3	2	-
11th	5	4	2	-
12th	6	4	3	-
13th	6	5	3	2
14th	6	5	4	2
15th	6	6	4	3
16th	6	6	5	3
17th	6	6	5	4
18th	6	6	6	4
19th	6	6	6	5
20th	6	6	6	6

Combat Casting: A hexblade of 5th level gains Combat Casting as a bonus feat.

Shadow Sight (Su): A 5th level hexblade's vision improves through his arcane ability.  He gains darkvision out to 60 feet, or increases any existing darkvision by +30 feet, and he gains low-light vision or increases the multiplier of any existing low-light vision by 1.
   The hexblade can also now see through magical darkness.  It appears as nothing more than a faint haze that does not impede his vision in any way.

Dire Draw (Su): Upon reaching 6th level, a hexblade can start bringing others to him.  As a swift action, a hexblade can target a single creature up to 10 feet away per hexblade level and attempt to magically teleport it to right beside him, though it does not actually utilize extra-planar travel.  The target gets to make a Fortitude save (including constructs and undead, even though this ability does not normally function on objects) with a DC of 10 + ½ the hexblade's class level + his Charisma modifier in order to negate the movement.  If it should fail, it immediately appears in an adjacent unoccupied open space of the hexblade's choice.  If there is no space available, it is placed in the closest open space possible to the hexblade.  This can be used to drop foes into hazardous locations if the hexblade is right beside it, such as off a cliff or into a fire, or to pull allies out of harm's way.
   A hexblade can use this ability three times per day, plus extra uses equal to his Charisma bonus (if any).  A use is not consumed if the target succeeds on its saving throw, however.

Improved Hexblade's Curse (Su): A hexblade of 7th level has a stronger Hexblade's Curse.  From now on, the penalty inflicted by it is -4, the spell failure chance is 20%, and he can have 1 more active target at once (minimum 2).

Aura of Unluck (Su): At 8th level, hexblades begin radiating bad luck for his foes.  All enemies within 30 feet of the hexblade must make a Will save, DC 10 + ½ the hexblade's class level + his Charisma modifier, or suffer from terrible luck.  An affected enemy must roll twice every time they make an attack roll, and they must take the worse result.  Casters affected by the aura must roll twice for any chance at spell failure, whether due to deafness, Hexblade's Curse, arcane spell failure due to armour, or any other similar effect.  If the afflicted enemy has the ability to reroll his attack or failure chance, he can reroll one of the two rolls, and must use the worse of the new roll and the one not rerolled.  Should anyone succeed on their save against a hexblade's Aura of Unluck, they are immune to that hexblade's aura for 1 day.  Once affected, the enemy suffers the aura's effects whenever he is within its area for the rest of the encounter.  If he should later enter the hexblade's aura again, he must make a new saving throw.
   If an enemy is immune to curses, he is immune to this ability.  Remove Curse or other similar effects cast on anyone affected by Aura of Unluck become immune to its effects for a number of rounds equal to the level of the spell cast, or ½ the caster's level if it has none.

Quick Cast (Su): Beginning at 8th level, a hexblade can cast one spell each day as a swift action, so long as the casting time of the spell is 1 standard action or less.
   He can use this ability one extra time per day every 3 levels thereafter (11, 14, 17, 20).

Bestow Curse (Sp): At 9th level, a hexblade can start placing the more common curses on others.  He gains the ability to cast Bestow Curse as a spell-like ability once per day, plus one every 5 levels beyond 9th (2 at 14, and 3 at 19).

Greater Shadow Sight (Su): A 9th level hexblade's sight is magically strengthened further.  He gains another +30 feet to his darkvision.  He also gains blindsight out to 30 feet, as he begins to mystically observe his surroundings without needing to use his own eyes.

Insidious Curse (Su): At 10th level, a hexblade gains a new way to use his Hexblade's Curse.  If he chooses to use a full-round action to activate his Hexblade's Curse, the range increases to medium (100 feet + 10 feet per level), there is no saving throw to resist it, and the duration becomes 1 hour.  It otherwise follows all the rules of the Hexblade's Curse.

Greater Dark Companion (Su): Also at 10th level, the shadows comprising the hexblade's dark companion become a bit more real and tangible.  The penalties inflicted by the companion improve to -3, and extend an extra 5 feet further, as if the dark companion had a 10 foot reach.  The dark companion can now also flank adjacent foes, though it has no attacks of its own.  It merely poses a seeming threat to enemies, causing them to have to split their attention.
   Alternatively, the companion may now be summoned without form.  It is effectively naturally invisible, and even True Seeing or See Invisibility cannot reveal it.  The companion will provide no flanking bonuses, because it cannot be detected, but its aura still inflicts penalties on all enemies in range.

Curse Eater (Su): Once a hexblade reaches 11th level, he becomes immune to curses.  Any spell or effect that can be dispelled or cancelled with Remove Curse has no effect on a hexblade.  Cursed magic items impart no penalties and can be discarded or removed without a problem.  However, some things beyond mortal power, such as artifacts, may have cursed properties, and are likely too strong for even a hexblade to ignore.  If any such item cannot be affected by Remove Curse, it is able to function on a hexblade as normal.
   Some supernatural diseases are also curses, such as mummy rot and lycanthropy, and therefore the hexblade is immune to these diseases.
   The hexblade can also Remove Curse with a touch, once per day, as a superatural ability.

Spell Resistance (Su): After reaching 12th level, a hexblade's resistance to magic becomes even stronger.  From now on, he has spell resistance equal to his class level + 10.  He can lower this as normal (requiring a standard action to lower it for 1 round).

Greater Hexblade's Curse (Su): At 13th level, Hexblade's Curse grows stronger still.  It now inflicts a -5 penalty, the spell failure chance increases to 25%, and he can now have another active target, bringing the active targets he can have cursed at once to a total of his Charisma bonus +2 (minimum 3 total).

Greater Aura of Unluck (Su): Also at 13th level, the hexblade's Aura of Unluck becomes more powerful.  It now affects foes' skill checks and ability checks, in addition to their attack rolls and spell failure chances.

Insidious Aura (Su): Upon reaching 15th level, a hexblade's Aura of Unluck becomes harder to properly resist.  When making a saving throw against Aura of Unluck, the foe must make 2 rolls and use the worse result, as if his saving throw were affected by the aura.

Dire Dark Companion (Su): At 16th level, a dark companion coalesces into a being of pure darkness.  It now imposes a -4 penalty to all enemies within 15 feet of it.  It also gains a natural attack, using the hexblade's base attack bonus + his Charisma modifier to determine the attack bonus.  This attack only has a reach of 5 feet, meaning the dark companion can only attack adjacent foes, or those in its own space.  It deals 1d8 damage + the hexblade's Charisma bonus (if any) to any foe it hits, and it can even make an attack of opportunity each round.  A dark companion's attacks overcome damage reduction as if it were magic and cold iron, and counts as bludgeoning, piercing, and slashing, just like a bite attack, regardless of what the dark companion's physical attack looks like.  Protection from Evil or similar effects do not prevent these attacks like they do against the natural attacks of summoned creatures, because a dark companion is not actually a summoned being.
   The dark companion is still intangible enough that it cannot be harmed, even though it can manifest an actual physical attack of its own.
   If it is summoned formless, the dark companion has no attack, and only gains the benefits of increased aura range and the stronger penalty it inflicts.

Superior Shadow Sight (Su): The hexblade's magically enhanced sight improves once more at 16th level.  His darkvision and blindsight both extend another 30 feet, and his low-light vision multiplier increases by 1.  He also gains continuous See Invisibility, as the spell.

Heart of Darkness (Su): A hexblade that reaches 17th level becomes immune to negative energy and death effects.  If the hexblade is undead, however, he instead becomes immune to positive energy and turn/rebuke undead.

Greater Bestow Curse (Sp): At 17th level, the hexblade's Bestow Curse ability becomes stronger, and from now on he casts Greater Bestow Curse with each use of the ability, instead of just Bestow Curse.

Dire Aura of Unluck (Su): At 18th level, the hexblade's Aura of Unluck expands to affect caster level checks made by affected enemies in order to overcome spell resistance.

Dire Hexblade's Curse (Su): At 19th level, Hexblade's Curse reaches its most powerful.  From now on, the penalty inflicted is -6, spell failure is 30%, and the hexblade can now target a group of enemies.  He can select targets so long as no two are more than 30 feet apart, and can choose the order they are affected in, until either all of them have attempted their saving throws or the maximum number of active targets is reached.  Also, the maximum number of active targets he can have afflicted is equal to his Charisma bonus +3 (minimum 4).
   If using Insidious Curse, the hexblade can only target a single creature each time, even with Dire Hexblade's Curse.

Paragon of Misfortune (Su): A hexblade that reaches 20th level reaches the pinnacle.  He gains a permanent +2 bonus to both Strength and Charisma, and from now on every enemy which attacks the hexblade must make two attack rolls, two spell failure chances, and/or two caster level checks to overcome the hexblade's spell resistance, and must take the worst roll, as if he were affected by the hexblade's Aura of Unluck, even if he has successfully saved against it or is outside its range.



Ex-Hexblades
   A hexblade who becomes good-aligned loses all hexblade spells and all supernatural abilities.  His dark companion dissipates, and he will need a new ritual to create another should the hexblade ever return to a non-good alignment.  He may not gain any more levels in hexblade, though he does keep all other class abilities (feats, proficiencies, and Mettle).



Spell List
1st: PHB - Alarm, Arcane Mark, Cause Fear, Charm Person, Disguise Self, Entropic Shield, Expeditious Retreat, Identify, Magic Weapon, Mount, Nystul's Magic Aura, Protection rom Chaos/Evil/Good/Law, Sleep, Tasha's Hideous Laughter, Undetectable Alignment, Unseen Servant
   CM - Bloodletting, Catsfeet, Death's Call, Karmic Aura, Reaving Aura
   CS - Armour Lock, Mage Burr
   PHB2 - Blade of Blood, Stay the Hand
   SC - Backbiter, Benign Transposition, Phantom Threat, Swift Invisibility

2nd: PHB - Alter Self, Blindness/Deafness, Bull's Strength, Darkness, Eagle's Splendor, Enthrall, False Life, Glitterdust, Invisibility, Mirror Image, Protection from Arrows, Pyrotechnics, Rage, Resist Energy, See Invisibility, Spider Climb, Suggestion, Summon Swarm, Touch of Idiocy
   CM - Animate Weapon, Arcane Turmoil, Bothersome Babble, Karmic Backlash
   PHB2 - Curse of Arrow Attraction, Ray of the Python, Scattering Trap
   SC - Baleful Transposition, Bladeweave, Curse of Ill Fortune, Curse of Impending Blades, Greater Alarm, Shadow Mask, Whirling Blade, Wraithstrike

3rd: PHB - Arcane Sight, Charm Monster, Confusion, Deep Slumber, Dispel Magic, Greater Magic Weapon, Invisibility Sphere, Nondetection, Phantom Steed, Poison, Protection from Energy, Repel Vermin, Slow, Stinking Cloud, Vampiric Touch, Wind Wall
   CM - Hood of the Cobra, Nightmare Terrain, Phantasmal Strangler
   CW - Hound of Doom
   PHB2 - Alter Fortune, Legion of Sentinels, Phantom Battle
   SC - Blacklight, Mass Curse of Impending Blades, Ghost Touch Weapon, Mass Resist Energy, Shadow Binding, Spectral Weapon, Unluck

4th: PHB - Baleful Polymorph, Break Enchantment, Contact Other Plane, Detect Scrying, Dimension Door, Dominate Person, Enervation, Fear, Greater Invisibility, Phantasmal Killer, Polymorph, Scrying, Sending, Solid Fog
   CM - Finger of Agony, Horrid Sickness, Karmic Retribution, Unseen Strike
   CS - Spell Theft
   PHB2 - Call of Stone, Crushing Grip, Friend to Foe, Greater Mirror Image
   SC - Assay Spell Resistance, Crawling Darkness, Cursed Blade, Mass Curse of Ill Fortune, Ruin Delver's Fortune, Sensory Deprivation, Sword of Deception, Vulnerability