Knowing Oro he'd probably feel Torune out with a double, then kill him. Or kill him from long range with a zillion snakes. Assuming this is a bloodlusted fight, Oro has no reason to get close. If Torune somehow does get close, and kills some of his cells, Oro can just get some distance and regen with body shed. Plus, Oro can't really die conventionally. Even if he was tied up helpless, and Torune destroyed his body, he'd probably have some contingency to rebirth himself in the long term, though I guess in those circs he'd lose the fight... unless he has really good genjutsu we haven't seen (assumedly he does, but since it's nearly featless we can't grant it to him)