Q: Why so complicated?A: This is one of the highest melee damage combinations in the game and it doesn't sacrifice defense to pull it off.
Q: Can you back that damage claim?Yep, without items you have +2 with Dueling, +3 from 3/day Rage, +5 from untomed Charisma, and +1d8 for Improved Smite on top of matching the Strength of any other mundane. Plus you can pop Elemental Weapon using your own Slots if need be. At 29 Str, Flame Tongue, & Hunter's Mark you have two Shortsword, 1d6+19+1d8+3d6 (37.5), and two Unarmed,1d4+17+1d8+1d6 (27.5), attacks for 130/rnd. You can then dump additional Spell Slots and additional Ki for Smite (up to +4d8/att) and Fangs (+1d10/att & up to 3/encounter) to really burn through your opponents.
In prospective, a Barbarian @29 Str, +4 damage from Rage, 2 attacks, Flametongue/Hunter he only hits for 2d6+14+3d6 (63/rnd) without the Great Weapon Master Feat. With it and Frenzy he swings for 124.5 which is still just a hair lower than you. And a Monk @29 Str, Flametongue/Unarmed/Hunter's Mark hits for 89 with Flurry of Blows. Burning Ki brings him to 111 which is also lower than you. However, thanks to Action Surge and Extra Attack(3) a pure Battle Master Fighter does deal more than you so you can't win them all. But think of it this way, he is your minion and if he ever turns on you then you have several undead creatures to eat him for lunch.
Q: Can you back that defense claim?You can wear Mithral Full-Plate for AC and have Paladin Spells like Freedom of Movement. You have 18 Constitution before Items, 12d10+8d8 for HP which isn't bad, Lay on Hands and Spells for healing and expending Hit Dice while resting has a +4 minimum value in a pinch. Plus while Raging (3/long rest) you also are Resistance to everything but Psychic Damage which is pretty defensive HP wise. Your Saves are amazing, Proficient Str/Dex/Wis Saves, add your +5 (or higher) Charisma Bonus to all Saves, and have an Advantage on Saves vs Magic.
Q: What about the overlord claim?You won't have the Animate Dead slots of a pure Oathbreaker, Cleric, or Sorcerer. However thanks to Wights & Vampires under Control Undead you have no theoretical maximum either allowing you to control just as many as any other. And I mean you
can become a vampire, but unless the campaign is set at night, or underground, or on another plane, you're kind of screwed.
Unless you're the DM. In which case this guy as a vampire is a badass mother father gentlemen that'll serve as your BBEG.
Q: Disciple of the Elements instead of Way of the Empty Hand, shenanigans!Elements lets you use Fire Fangs which gives +1d10 per ki/attack. Numerically using your Ki for Flurry of Blows over four rounds is better than dumping it into Fire Fangs but for lower level Encounters or when playing with other optimized players being able to burn your Ki for an extra +16.5 damage in a single round has it's advantages.
Empty Hand on the other hand let's you attempt to Trip people with each Unarmed Strike, effectively you'll burn one Ki for Flurry and make them Save twice vs Trip. Combined with 5th's ability to Move before, during, and after your Attacks you can attempt to flee from them once they are knocked down. However unlike 3rd/3.5/4th standing up is not a separate Action on it's own anymore and you do not get extra attacks either. All it does really is cut their Speed in half for one round (assuming they don't have the feat that reduces it to 5ft), so you need a massive Speed value over theirs in order to move in, hit-trip, and move away far enough they cannot hit back. And you're supposed to do this in Full-Plate
Q: Why a build guide? I want a class guide!A: And I want splat so there's a reason to writing a Class guide beyond goddammitwhatspellsareonmylist!
Q: Goddamit, what Spells do Paladin's have anyway?Let me help you with that.Q: I don't like how the tables move around.A: That's not a question.
Q: What about replacing the last part of Monk there?A: To be honest I'm on the bench for that. Each class has their own merits (see 2nd post), if you're wanting pure damage consider Fighter for Action Boost another Attack Action (which benefits from extra attack) which takes your potential average to 205 for the first round before Smite.