Ultima Cannon (アルテマキャノン Arutema Kyanon ) is a technique that appears in Kingdom Hearts II Final Mix and Kingdom Hearts Birth by Sleep. The technique transforms the user's Keyblade into a large cannon that launches large spheres of pure energy at the opponent. It is first used by Terra and is passed on to both Terra-Xehanort and Terra's Lingering Will.
In Kingdom Hearts II Final Mix, the Lingering Will's Ultima Cannon fires one sphere of energy that homes in on its target and produces a larger explosion than Terra's version. However, the explosion is weaker, and the sphere can be deflected back at the Lingering Will.
In Kingdom Hearts Birth by Sleep, Ultima Cannon is Terra's ultimate Shotlock. It has a maximum level of 6 and max lock of 16. After the first sphere of energy is fired, the player can increase the damage of a second sphere by pressing when prompted. The better the player times their button press, the more powerful the second energy sphere is.
 Learning Ultima Cannon
 Kingdom Hearts Birth by Sleep