The Black Magic Revolution
As the name suggests, it holds the spirit of Yulai, an ancient being of great magical and spiritual power. Chances are, you would inherit some of her power should you wear her pin, if her power does not consume you first.
Level 4 BMV
The user gains +2 DEX and +2 CHA
The user grows 4 tails and fox ears. Their eyes become more vulpine-like and grant low light vision. They can hide these changes as if using disguise self, but only to appear as they were before the change. While hidden, the user cannot use any of the abilities.
For 1 charge, the user can attempt a melee touch attack as an attack action on the opponent. If they hit, the enemy gains 1d4 temporary negative levels, and the user gains that many temporary levels (but only for attack, saves and hp) These last up to caster stat hours.
By using 2 charges, the user can cast Enervate as a spell like ability.
By using 1 charge, the user can fire a bolt of negative energy for 4d6 damage as a ranged touch attack. If the person hit can cast divine spells, they take 8d6 instead.
By using 4 charges, all enemies within 200 feet are blinded momentarily. You swap places with an enemy and assume their appearance while they assume yours. A DC 15+caster stat + half level will save sees through the illusion. the one being swapped with must make a DC 10+caster stat+half level FORT save in order to negate the effect entirely.
Charges per day = 4+caster mod