True Sigil of Power

Description
A small shining black disk with one half covered by a small curved teardrop ruby that glimmers brilliantly with a smaller circular sapphire ingrained into the large round portion of the ruby. The gems even seems to glow slightly, and there's a small indent on the other half of the disk where it seems like another gem should be.

Effect
Allows access to Sofia's 3rd fight, out of combat sex options with the Onis, and the option to fight them at their full strength from the beginning.

Obtaining
Defeat both Mizuko and Himika in their optional 'fight both at once' fight.