Sparadrap entering Unstoppable Rage mode in the Season 4 finale after Roxana insults him, his grandma and his team, declares her intent to kill his whole group, and then proceeds to steal and kill al of his familiars. Even though it ultimately fails, seeing him unleash a wave of obliterating magic on her is pure awesomeness, especially when you take in account how incompetent he usually is in battle. And no, it wasn't his brother controlling his avatar. It was all him.
Sparadrap : "There are three things which you shouldn't do in front of me... Make fun of my grandma, hurt my friends... and above all, KILL MY FAMILIARS!"