This is what I came up with: Tiefling Warlock
For this character sheet, I’ve left off most of the personality details, feeling they’d be filled in by the player. (At some point, I may add a second page of suggestions).
His request for a Chaotic Neutral Zhentarim made the choice of patron quite interesting. Chaotic doesn’t lend itself to the Lawful Evil devils that well. After considering that the character was going to be playing Out of the Abyss, I chose the Archfey patron, as having faerie fire is a particularly useful spell. (That, and I’ve seen entirely too many fiendish patron warlocks of late. I like to mix things up!)
I’ve also experimented a little with a Zhentarim symbol as the watermark, and a Warlock class symbol in place of a class portrait.
This character, as it goes beyond the basic rules, requires a Player’s Handbook to play, although I’ve tried to give enough reminder text so that constant reference isn’t necessary.
What do you think? (I really do need to add more personality and history notes…)
(Per a request, here’s a Tiefling Warlock – Fiend pact)
EDIT: Revised both characters to fix errors in spell list. Thanks to Daniel Taylor for his comments!