The Possessor is a music from the Shovel Knight soundtrack. This is the battle theme of the Enchantress and a medley of dramatic arrangements of the Main Theme and The Starlit Wilds. It is Music Sheet #43 in Shovel of Hope and can also be listened to in Sound Test after completing any campaign once.
Music Sheet #43 and can be found in Tower of Fate: ????, in the room far left from the bottom of the pitch black room with invisible platforms.
"If you could only convince her to listen to reason! Alas... battle it is."
- "Bard: Let's see here... Oh, you found "The Possessor"! Say what you will about the Enchantress, but she was great to work with. Gave me this pretty amulet, too!"