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