The Familiar of Zero — S1E2 · The Commoner Familiar

An abrupt departure from the normal life he once lead, Saito must deal with being Louise's familiar. Unhappy with the arrogance of nobles, Saito exposes Guiche's two-timing nature as an act of revenge. This of course, provokes Guiche into challenging him to a a duel. Despite being severely beaten up by Guiche's magic, Saito refuses to bow down. Impressed, Guiche tosses him a sword to even up the playing field. In a completely unexpected turn of events, the runes etched on Saito's hands begin to glow the moment he grasps the sword. Feeling a surge of energy, Saito manages to defeat Guiche. However, he soon collapses after the fight from fatigue.