Complex sentence: At this point it is revealed that, during the Bakumatsu, Kenshin used to be married to a woman called Yukishiro Tomoe, who initially wanted to avenge the death of her fiancé, whom Kenshin had killed, but instead both fell in love and got married.
Split into simpler sentences: At this point it is revealed that, during the Bakumatsu, Kenshin had been married to a woman called Yukishiro Tomoe. She had initially wanted to avenge the death of her fiancé whom Kenshin had killed, but instead both fell in love and got married.