Well, this chapter shed some light on Ji-tae's motivations again. It boils back down to "Ji-tae hates himself for being so weak" again, but we can see it manifest more clearly here. From ch 72 we know
he HATES fighting. He clearly despises the fighters here: they actively choose to hurt others, and when they are on the receiving end of pain, suddenly they're not a fan of fighting. But it's not like he wants to teach them that lesson. He only wants to do this because he "feels like shit": he fights so violently here to repent for his weakness in the past, unable to save Ok-dong and relying on others to do that. He fights so violently because he hates himself, and hurting others is his punishment for his weakness.
He also sees himself in Da-hye, based on the parallels that
@mylastchance89, and on page 28, where he says that "shameful death is the only way for
us to repent". Yet, even after getting slashed by Da-hye, it looks he hasn't hurt her at all. He wants Da-hye to know the true pain of fighting, hurting others, and not being able to protect those she care for. He wants to see whether she chooses to run from fighting, or to stand up and
earnestly try to kill him, granting them a chance to repent for their violence.
Once again, thank you for the scanlations.