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