After Choso attacked you with his "Piercing Blood" ability and you managed to hit Choso and he blocked the blow, he would stop attacking and then ask you what his brothers said before you killed them. "No, not really. But... They were crying." After you said that, Choso would immediately become furious like never before. "Eso... Kechizu... Watch over me... This is your older brother!" A massive amount of blood would come out from his back, covering the entire roof of the station. After a few moments all the blood would gather on her right hand until it formed a small circle of blood.