Spirit Stone

"As light as a feather, and you can almost see through it. Some people say looking at it for too long can change your personality."

The Spirit Stone is a Reforge Stone that applies the Spiritual reforge on any Bow. It is currently considered the best bow reforge on bows which aren't Terminator in dungeons. It can be found on The Catacombs - Floor IV.

Dungeon Reward Chests
The Spirit Stone has a chance to drop from Diamond, Emerald, and Obsidian Dungeon Reward Chests on The Catacombs - Floor IV.

Thorn
The Spirit Stone can be obtained from, after killing Thorn 50 times.