Undying Sincerity - S2.E4

Saito follows Sannan out at night, but loses him when he sees Amagiri killing a Rasetsu. In return for helping him kill the Rasetsu, Amagiri tells him a shocking secret about the Rasetsu. Saito relays this information to the Shinsengumi, and Hijikata orders Sannan to stop all experimentation on the Rasetsu Unit. They also decide to move to Aizu. Chizuru witnesses Hijikata having a vampiric impulse, but Hijikata refuses to let her give him some of her blood. Later, after the Shinsengumi make camp in Aizu, the enemy decides to attack the headquarters when all of the troops are out for training. Kondou orders Hijikata and the rest to escape while he stays behind. As they escape, they run into enemy soldiers. Despite Chizuru's plea, Hijikata uses his Rasetsu powers and kills them all. Kondou peacefully surrenders to the enemy, and Hijikata angrily laments his choice to leave Kondou behind.