The Coup de Grāce Cutscene after beating Moltaan. He stumbles and falls into the volcano... which normally wouldn't do anything, since he's already made of lava... And so Oliver casts Pulse to drop a gigantic firggin' rock on his head, plugging the erupting volcano at the same time.
How about Drippytossing the Golden Grove boss' shield back at him!? And take note, that shield was ten times heavier and bigger than he is!
Alicia's entire plan which involves her going to the alternate world and becoming Oliver's mom.
Nearly every Miracle Move could count. Mites slice through the air with so much speed and power that they shred the enemy to pieces. Hurlies punch the ground to summon a pillar of fire. But best of all is Oliver's Burning Heart. By summoning all of his magical power Oliver creates a giant ball of fire which he then throws at the monsters and burn them to a crisp in a all hitting blast of fire. A shame fire enemies can resist it.
Unleashing. It's a blast summoning the bosses you've defeated and using their signature moves against your foes.
Battling Shadar, as well it should be. Every last phase of it.
Phase 1: Shadar the Executor. It's payback time for the butt-kicking he gave you on the boat. Just like last time he tosses Pyres, Fell Winds and Bleak Midwinters with impunity, but you have Mornstar, so now you can...wait...what the heck is EVENSTAR?!?
Phase 2: Eternal Knight, Darkest Demon of Despair. Shadar's personal familiar, an evil counterpart to none other than the mite you get at the start of the game, right down to its signature attack. The beast is a juggernaut of destruction, but after a long battle, you finally take it down, convincing Shadar to take off the kiddy gloves...
Shadar: So you have defeated the soldier of my soul...impressive. But when despair consumes the heart, it gives birth to a power still more terrible. It is despair that will defeat you! You and all else! I am The Executor, charged with bringing destruction to this world! Behold...the power...OF THE DARK DJINN!