My apologies if these ideas have already been posted... hope you enjoy!
Dumb Luck (Trait)
"Better lucky than good..."
Small chance to reroll to-hit if missed. In addition, small percent chance to upgrade an item one step up.
For example, a small health pack might upgrade to a large health pack.
Angel of the Imp (Angel)
"Rawr!"
This could be really fun, if done correctly. Tired of getting snuffed out by blood-thirsty marines, you have decided to take matters into your own hands. As an imp, you are bottom rung of the demon hierarchy... until today. Claws and Imp Fireball, the weapons of choice.
Angel of Skulls (Angel)
"Noi eravamo quello che voi siete, e quello che noi siamo voi sarete."
High spawn rate of lost souls. Very high. Start with 2 phase devices.
Angel of Perfection (Angel)
"Flawless victory!"
Stairs will only function if the player is at 100% health. (Pretty tough.)