Here is the full list of all 37 Midnight Castle Succubus DX achievements.
Use another succubus hunter after clearing
Use another succubus after clearing
Rescue and clear all girls
Defeat the shadow of the succubus
Make map reach 100%
Rescue all girls
Take all the red gems
Take all crowns
Defeat the prison mother
Defeat the Necromancer
Defeat the Dark Elven Queen
Defeat the Queen of Flames
Join the mage
Defeat the Mermaid Queen
Defeat the Queen of Masks
Transform into a succubus
Defeat Succubus Second Form
Defeat the succubus
Defeat Dryad
Join the warrior
Defeat the Queen of Mud
Defeat the Sphinx
Join the monk
Defeat Harpy
Join the Thief
Defeat Undine
Take the first crown
Take the first red gem
Rescue the first girl
Defeat the Statue
Complete without rescue a single girl
Complete without taking a crown
Clear without taking the red gem
Use the Goddess of Revenge after clearing
Complete without rescue a girl
Rescue and clear one or more girls
Bad, good, best, see all three endings