Here's my first try. Anything not from the previews and tidbits people have leaked is assumed unchanged from the leaked Alpha (which I know is dubious).
Vorn, human fighter1/warlock5
HP: 22+5d8 (or 47)
Stats: Str 16, Dex 8, Con 14, Int 10, Wis 8, Cha 16
Saving Throw Proficiencies: Con and Str
Skills: Intimidation, Athletics, Persuasion, Arcana
Feats: Greatweapon Master (lvl1), War Caster (lvl4)
Fighting Style: Defense
Invocations: Devil's Sight, Mask of Many Faces, Thirsting Blade
Pact Abilities (Archfiend): Dark One's Blessing
Spells:
Cantrips: Chill Touch, Eldritch Blast, Mage Hand
Level 1:Charm Person,Thunderwave
Level 2
arkness, Ray of Enfeeblement
Level 3: Fly, Fireball
Vorn was born scion to a minor noble family, and quickly became obsessed with improving his skill on the battlefield and spreading the glory of his family name. When he heard of a cursed blade that could claim men's souls for the promise of power, he didn't hesitate to seek it out. He may have gotten more than he bargained for...
Vorn likes to call on the dark soul of his blade (which usually takes the form of a massive greatsword) to mask the battlefield in Darkness as he enters the fray (since he can see through it with Devil's Sight). He can use Ray of Enfeeblement as an opportunity attack, cursing those who would shun face-to-face combat, and picking off distant foes with Eldritch Blast or Fireball when necessary. He also doesn't hesitate to fly around in battle, since Con proficiency plus War Caster makes it almost impossible to break his concentration.