The Trance/Limit Break system from Kingdom hearts 2 comes to mind.
Become one with your allies to turn the tide on the enemy!
This form obviously is Reimu + Nazrin;
Traits: Auto-Brave, Auto-Regen, Flee, Dual Wield III, Auto-Phalanx, Auto-Haste
Reaction Command: Compass Cleave; Preformed after deflecting an incoming enemy attack, Reimu preforms a wide cleaving strike to attack and blow away enemies.
Final Attack: Guided Pendulum; Reimu instills her Fantasy power into her Pendulum crystal, making it increase in size and has it bombard itself onto the enemy, resulting in a barrage of crystal shards as it explodes. Enemies defeated by this attack have a higher rate of dropping Prize orbs