Copycat: 2/day for each HD it has as a standard action, a doppelganger can assume the shape of any Small or Medium humanoid as per the Change Shape ability. In humanoid form, the doppelganger loses its original natural attacks. A doppelganger can remain in its humanoid form until it chooses to assume a new one. A change in form cannot be dispelled, but a doppelganger reverts to its natural form when killed. A true seeing spell or ability reveals its natural form.
In alternative, the doppelganger may simply change its surface aperance as with a Disguise Self spell, except that it is a physical change and thus counts as a transmutation effect and not as an illusion effect. This option doesn't expend any uses, being useable at will and as a move action to boot.
Adapt: The doppelganger gains a bonus to his ability scores equal to his class level, which can be divided among his ability scores in any way he wishes. He may reassign these bonuses as a swift action.
Mind read: A doppelganger can continuously use detect thoughts as the spell (caster level equal to HD; Will DC 10+1/2HD+Int modifier negates). It can suppress or resume this ability as a free action, but can only use it a total number of rounds per day equal to its HDxInt modifier.
In addition, the doppelganger is now immune to sleep and charm effects.
Weaver of lies: the doppelganger gets a bonus on bluff and diguise checks equal to its HD. If it is sucessfully reading the mind of the person it is trying to fool, this bonus doubles.
In adition, if using the change shape ability, it gets an extra +10 on disguise checks(wich is doubled if sucessfully reading minds).
Trapfinding: As the rogue ability.
Greater Adapt: The doppelganger gains a bonus to his ability scores equal to his class level, which can be divided among his ability scores in any way he wishes, though if he applies bonuses from Adapt and Greater Adapt to the same stat then they do not stack. He may reassign the bonuses from both Adapt and Greater Adapt as a single swift action.
Powerful Fist: A Greater Doppelganger forced back into its original form is still an enemy worthy of respect. At 2nd level the Greater Doppelganger's slam attack gains a +1 enhancement bonus per 5 HD, and a bonus on attack and damage rolls equal to his Int modifier. The doppelganger may also choose to spend some or all of its slam's enhancement bonus on weapon enchantments from the table below. It can reassign these bonuses as a swift or move action.
Polymorph Rend: Greater Doppelganger are masters of form, and they don't like competition. At 3rd level the Greater Doppelganger is automatically aware if any creature inside its natural reach is in a form other than its own. As a melee touch attack you may inflict 1d6 damage to such a creature as you turn their fake form against them, +1d6 damage per 2 HD you possess. In addition, the subject must make a Fort save (DC = 10 + half your HD + your Int modifier) or be forced back into its original form; creatures with the shapechanger subtype gain a +4 bonus on saving throws against this effect.
Innocent Intentions: At 4th level the Greater Doppelganger is automatically aware of, and immune to, attempts to magically discern its alignment, though this does not provide it with knowledge of the effect's source. While wearing a consumed identity, it may choose to radiate the identity's alignment instead of blocking the effect.
Double Fist: At 4th level the Greater Doppelganger gains a second slam attack, which also benefits from Powerful Fist. Enchantments applied to its slam attack apply to both slam attacks.
Magic Item Use: At 5th level, when a Greater Doppelganger assumes a different form, its magic items continue to function even while melded into its body, though they continue to take up body slots. Any magic auras those items would normally have are concealed while melded into the Greater Doppelganger. It may choose to meld items into its body even if its new form is capable of wearing them normally. The Greater Doppelganger cannot "remove" melded items without returning to its natural form, though it may still wear items over them (which suppresses the melded item's effects, as normal for wearing two magic items in the same slot). A Greater Doppelganger is always capable of fine manipulation, even if its current form has no suitable limbs.
Assume Identity: An ethereal doppelganger can copy another creature's mind, memories and personality. It cannot Assume the identity of a creature with more HD(actual HD, not counting any modifiers like enervation or bardic music or whatever) than its Ethereal doppelganger levels+Greater Doppelganger levels. This process requires 1 hour of unbroken physical contact. The target may attempt a Will save with DC 10+1/2 HD+Int mod, if that is successful, the process is negated and the ethereal doppelganger must begin anew. A willing creature can choose to fail the saving throw. If the target's CR is equal or lower to your Ethereal Doppelganger level they get no saving throw tough.
After copying the target creature's identity, the ethereal doppelganger may choose to assume that creature's form with its Copycat ability (rather than just a generic member of its species), and does so with 100% accuracy, possessing the victim's memories, abilities and personality, though the doppelganger still possesses its original alignment (this includes all Ex, Su and natural abilities, but not ability scores, HP, base saves, the doppelganger can use either its own skill points or those of the victim, whichever's better at the time, it must rest to recover spells in the case of spellcasters and similar). Spells, items and effects keyed to the worn identity treat the doppelganger as if it were the original creature (eg. if the doppelganger assumed the identity of a creature who had been designated as an allowed user of a phase door at casting time, it would be able to use the phase door as if it were that creature). When making a Bluff or Disguise check to impersonate the creature the Doppelganger's racial bonuses are doubled, though this does not stack with the bonus from reading minds. Using Copycat in this manner does not expend a daily use of the ability.
Note this doesn't hurt the original creature in the slightest, the ethereal doppelganger is merely replicating its target. The Ethereal Doppelganger can have a maximum of 3 identities consumed at once, +1 per 6HD. If it would gain an identity in excess of this amount, it must "forget" an existing identity in order to learn the new one.
While using Assume Identity, the Doppelganger retains its own darkvision, plus any DR, fast healing and SR it may have. If the ethereal doppelganger commits an act that runs counter to its new identity's personality, it is immediately forced back into its natural form for 1d10 rounds.
Ethereal Doppelganger gains a +1 bonus on attack and damage rolls, skill checks, and the DCs of its abilities against Monstrous Humanoids.
Ethereal Sanctumt: The Ethereal Doppelganger starts the development of a building somewhere in the Ethereal Plane where it can rest and plot, up to 100 square feet per HD. This includes the stablishment of connections, contracts and wards to secure and supply the Ethereal Sanctum, meaning it allows for the confortable existence of one normal humanoid-sized creature per HD whitout risk of random attacks or exterior divinations detecting it, altough it is still vulnerable to anyone specifically hunting for the Ethereal Doppelganger itself should it let itself be seen in its original form by others.
Showroom-Filled with trophies of past adventures, refined art pieces, grandious statues and lavish furniture, this 1000 square feet addition is meant to impress visitors. The Ethereal Doppelganger gains a racial bonus on all Cha-based skills while inside this room equal to it Ethereal Doppelganger level+1/2 other levels, and can seek to forge a contract with any creature it brings here, even enemies, as a fullround action 1/day. If they fail a Will saving throw with DC 10+HD+Int mod, they accept for the Ethereal Doppelganger to use Assume Identity on them, and then they'll peacefull remain in the Ethereal Sanctum for up to one month while the Ethereal Doppelganger advances its own agenda. The Ethereal Doppelganger may try to renew the contract after 1 month is up, but the target gets a cumulative +1 bonus on its Will save for each extra month. The Ethereal Doppelganger is also responsible for the safety of its “guest“. It must make sure of its security and confort and then take them to an open, safe location of their choice when the contract is up. Should any harm come to them before that, the Ethereal Doppelganger automatically loses the respective Assume Identity and all benefits of the Showroom for 1 year and 1 day as it builds back its reputation.
Prison-A cold, dark set of corridors and cells up to 1000 square feet with reinforced gates, runed shackles, binded guardians and all other material needed to keep all manner of creatures confined. If you bring a creature whose CR isn't bigger than yours and it is mind-locked (either before or after entering the prison), they aren't geting out unless you let them to, even if they have teleportation, freedom of movement or similar. However the prison also increases the defiance of any victims-they no longer fail saving throws in a natural 1 and actually gain a +1 cumulative bonus on all saves each day they spend in it. Those bonus are lost as soon as the creatures are let free. If you let someone inside your sanctum under your trust and they try to take actions against you, they're automatically sent to the prison by the binded guardians.
Plane Shift: the Ethereal Doppelganger can use Plane Shift as a SLA 1/day per 4 HD. If he uses this ability to return to its Ethereal Hideout (or send others there), it spends no uses and always arrives precisely on-target. Save DC 10+1/2 HD+Int mod.
Ethereal Adapt: The doppelganger gains a bonus to his ability scores equal to his class level, which can be divided among his ability scores in any way he wishes, though if he applies bonuses from Adapt, Ethereal Adapt and/or Greater Adapt to the same stat then they do not stack. He may reassign the bonuses from Adapt,Ethereal Adapt and Greater Adapt as a single swift action.
Brain Lock: At 2nd level as a standard action, an ethereal doppelganger can lock away the higher mind of an opponent up to 20 feet per HD away, provided both are on the same plane and the ethereal doppelganger has line of sight to its subject. A successful Will save with DC 10+1/2+Int mod negates the attempt. Failure leaves the subject mentally paralyzed. A brain-locked creature is not stunned, so attackers get no special advantage against it and it retains its Dexterity bonus to AC (if any), but otherwise the victim cannot take actions. Brain-locked creatures flying automatically drop to the ground. Brain-lock lasts 1 round per HD, but the Greater Doppelganger can dismiss the effect earlier as an immediate action. If an opponent fails three saves in a row against Mind Lock, they're left unable to act until the ethereal doppelganger wills them free or they receive a Remove Curse or similar.
Versatile Skin: At 4th level the Ethereal Doppelganger's shapeshifting abilities have evolved to a point its body can instantly adapt to incoming attacks. It gains DR/silver equal to its HD and SR equal to 11+HD, which may be raised or droped at any moment as a free action, even if it isn't its turn. In addition while in its natural form it can, as a swift action, reshape its hands into claws (dealing slashing damage) or spikes (dealing piercing damage), replacing its natural slam attacks. The spikes/claws retain any benefits the slams had, including the Greater Doppelganger's Powerful Fists.
Abduct: at 4th level when using Plane Shift on an unwilling target, you can bring yourself along with them if they fail their saving throw.
