Here is the full list of all 16 Demons with Shotguns achievements.
You collected 500 souls!
You're an a' hole with how much you taunt.
You don't seem to understand how ammo pickups work.
You kept killing yourself.
You earned 5 Double Kills.
Flawless Victory!
You earned a Antichrist kill streak.
You completed Ghosts n' Nomeds.
You used 10 tarot cards in one match.
You jumped 100 times in one match.
Fighting for scriptures.
You earned 3 Monster Kills.