Because you like Torrance Shipman in Bring It On

A crabby troll, Karkat Vantas is perpetually angry about his lot in life. See them in Homestuck.

Everyone is just a chess piece, and Izaya Orihara is a master player. See them in Durarara!!.

The main priority for Nagisa Hazuki is making sure that everyone has fun. See them in Free! Iwatobi Swim Club.

Eren Jaeger will erase the Titans from this world until not a single one remains. See them in Attack on Titan.