The main character and primary protagonist of Aldnoah.Zero. He’s something of a physics nerd, and this allows him to understand the individual quirks of each Martian Kataphrakt quickly; consequently he has killed many Martians.
He also uses a training Kataphrakt rather than a regular military one, purely because the training one has less armor and is thus lighter. Because all training Kats are colored orange, he became easily identifiable on the battlefield.
Kaizuka is so great at piloting that he quickly propels himself to legendary status among the Terrans and Martians, no doubt helped by his relatively unique Kat. It’s somewhat unusual the UFE didn’t use him much as a propaganda tool^A).