The wound was already too deep, it was just a matter of time till he dies. And so he stabbed himself again refering as he's the one who did the final blow (he killed himself). Baji did that so he doesn't burden Kzutora for his death.
Fufufu... Kokonui ofc, draemma, takehina, Rinzu/Sanrin, Hakkamitsu, Rankazu, takeomishin, hankisa and lil bit wait no lil bit but y kisaki x truck kun 😍😍🔥 Maybe that's all (?) Hehee