Hajime Saitou is loosely based on the real third-squad captain of the Shinsengumi. During the Meiji era, he lived as a police officer under the name of Gorou Fujita. In the Rurouni Kenshin series, he plays the role of Kenshin's old rival and enemy from the Bakumatsu. He has no compassion or mercy for his enemies and he lives by the Shinsengumi code "Aku Soku Zan (悪即斬)," literally "Slay Evil Immediately," but more poetically rendered as "Swift Death To Evil." His signature technique is the Gatotsu, a left-handed thrust and a variation of the Hirazuki technique developed by Toshizou Hijikata, the Vice Commander of the Shinsengumi. Although the Gatotsu is a fictional technique only found within the Rurouni Kenshin series, the Hirazuki is a real technique that was used by many of the Shinsengumi members.

Notorious for his cruel and deceitful fighting ability, Hisoka has proven to be deadly. His deviousness and volatility has made many opponents have difficulty anticipating his next move, and this has led to him winning many battles. Using Shu powered poker cards as his primary weapon, he throws them with ease and deadly accuracy.

Also, he is very intrigued by Gon and the potential this young boy has to become an adept and powerful adversary. Hisoka, ever looking for a strong opponent, is willing to aid, or at least not defeat prematurely, someone that could develop into a future opponent.

Hisoka