Here is the full list of all 10 An Evil Existence achievements.
Enter_the_Hartley_household
Find_the_missing_jigsaw_piece_of_Darwen_Tower
Solved_the_disappearance_of Annabelle_Rhodes
Find_a_picture_of_a_baby
Escape_the_tomb_tunnel_fire
Find_out_who_the_corpse_in_the_bedroom_was
Meet_the_nun_ghost
kill_the_twin_brother_with_the_broken_cross
Kill_the_Hartley_Mother_with_the_flamethrower
Complete_the_game