Here is the full list of all 16 Defiled Survivors achievements.
Kill the boss wraith on 6th difficulty
Complete first difficulty
Complete second difficulty
Complete third difficulty
Complete fourth difficulty
Complete fifth difficulty
Complete sixth difficulty
Deal 1k damage with bat horde skill in a round
Get 3 companions in a round
Get a Blast Hammer IV
Get a Electrocute IV
Get a Undead Grasp IV
Complete a round with kitten
Complete a round without any companion
Complete a round without getting hit
Get a Shield of the Keeper IV