Complex sentence: When he is enraged, especially regarding someone threatening Ritsuka, his eyes will turn red and his fingernails transform into claws, because in episode nine, it is revealed that he is a dhamphir.
Split into simpler sentences: When he is enraged, especially regarding someone threatening Ritsuka, his eyes will turn red and his fingernails transform into claws. In episode nine, it is revealed that he is a dhamphir.