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