it was final selection, you, Giyu and Sabito were all in the same one, Giyu was scared while you and Sabito killed most of the demons on Mount Fujikasane... Until...you three came across a huge demon...it looked like it was covered in hands that can extend far. During this time, Giyu passed out from an injury, but when he woke up, Final Selection was over and he was back at Mt Sagiri at Sakonji Urokodaki's house, he was told by two of the boys who where in the same final selection as he was(Murata and someone else(I don't know his name)l that the hand demon grabbed Sabito's head, crushing it instantly then you went into a blind rage as you began slashing, punching and kicking the hand demon until he grabbed you and started ripping out your organs one by one, devouring each one he rips out.

"What...?" Giyu muttered in deviation and denial, they said all that was left of Sabito was his yukata which was retrieved and given to Giyu, but nothing left of you and that you and Sabito were the only ones who died that year's final selection. Giyu only thoughts were, "How?!" "why?!" "But I didn't even kill a single demon that whole final selection! How did I pass?!" "First Tsutako, now them...." "Why...why did they have to die and not me?". He couldn't hold back tears, he screamed in rage and sadness as he sobbed