A poor fellow, the Reaper was at first a farmer who made his way in the world. One day, his village was raided and put to the torch by marauding bandits. His family, his neighbours all dead. He himself left for dead. Impaled by a spear and barely clinging to life, the farmer awakened in the night to the sound of the bandits carousing and plundering the ruins of his village. He cursed the gods for his fate, and wished more than anything to avenge his family.
At that point, Boethiah's conduit appeared before the farmer, saying: "For this one night, I will grant you the power of death, if you serve me forever more." The farmer with his dying breath agreed to this bargain. All he had was his homestead and his family. "It is done," and with that, the avatar of Boethiah wrenched the spear from the farmer, transformed it into a spectral battleaxe, and disappeared. The farmer's wounds were gone. Grasping the ghostly battleaxe, the farmer became something more that night. With every chop, he disappeared into the shadows. With every slash, another bandit fell and was raised again to fight their previous comrades.
In the morning, the farmer awakened to the charnel stench of fetid meat and piles of ash. Distraught, the farmer heard a voice in his head: "Skyrim, go now." It was Boethiah's call, and it was then that the farmer remembered his deal. It was then that he realized, he had become The Reaper
-Nord, Breton or Altmer; Dunmer to a lesser extent but for the lore and vampirism
-Vampire Royal Armor, Morokei, Ring of the Erudite (decent armor stat and lots of spell casting)
-Nightingale armor (high armor stat, reduces illusion spell costs)
-Anything with "Fortify Two-Handed" on it. (necklace, gloves and boots)
-Bound Battleaxe, Rueful Axe, Skyforge Steel Battleaxe, Bloodskal Blade, Skyforge Steel Greatsword, Ebony Blade, Stormfang, Volendrung, Champion's Cudgel
-Bound Battleaxe, Frenzy, Route, Invisibility, Conjure Boneman, Conjure Mistman, Conjure Wrathman, Healing, Summon Arvak
optional: Muffle, Revenant, Dread Zombie, Soul Trap
-Shouts: Marked for Death, Become Ethereal, Soul Tear, Summon Durnehviir
ratio for Magicka
(All recommendations based on higher levels and end game. The journey there is half the fun! The Dragonborn DLC is not required for this build. The Dawnguard DLC is required for the "Conjure" spells)
The Reaper is intended to be kind of like a necromancer, but with more of a focus on stealth and two handed weapons for damage.
For roleplaying, the evil "I'm gonna kill you and everyone you know" seems to be about right. That, or a mercenary looking for adventure? A master of the dark arts trying to redeem his past? Oh, the possibilities! Become a vampire lord to embrace your eternal call. Be sure to be discreet with your murders, and reap only those that are deserving of death. Joining the Companions and the College of Winterhold is highly recommended for early game gear. Later on the Volkihar Vampires should be joined to obtain the "Conjure" spells and the Ring of the Erudite. Do the quest "Boethiah's Calling" as soon as you hit level 30 to prove your allegiance to the Daedric prince of deceit. After level 32 the Thieves Guild should be joined to obtain the Nightingale armor set. You do NOT need to be the "dovahkiin" with this build. In fact, I recommend a mod such as "Skyrim Unbound" with an alternate start to really get into the playstyle of this elusive dealer of death!
Start off a fight by sneaking in for a big ol' two handed head split or impale, or throw out a "distraction" with Conjure Wrathman/Frenzy/Route/Conjure Mistman/Conjure Boneman without grabbing too much attention thanks to the Quiet Casting perk. Using your summoned undead and illusions as a distraction, take any opportunity you can to perform a Sweep attack against grouped foes to cull the numbers. Quick Reflexes when blocking with your 2 hander should ease 1 on 1 situations with tough melee opponents. When ranged fighting is necessary, Twin Souls with a Mistman or a Boneman or two should do the trick. Got a lot of dead bodies around but still wading into the thick of it? That's what the Ritual Stone is for! Is the Ritual Stone not up to task? Then the Lord Stone should help keep you standing. When things get too hairy to handle: Invisibility and Shadow Warrior will get you out of nearly any situation, if not set you up for an in-combat sneak attack. Embrace the darkness!
While leveling, the Lover's Stone is highly recommended. For your two handed weapon, select a weapon type of choice and stick to it. Like greatswords? Use the Deep Wounds perk! Or, just don't specialize in a single two hander. Your choice, use what you prefer! I personally go for the Bound Axe for a more spectral scythe-ish look. Remember to smith up your armor and weapons with your Arcane Blacksmithing!