This fight is just really lame.
I would expect, from his backstory, that Naidan joined the Worm for his own sake, which means that he shouldn't be willing to sacrifice himself in a stupid way, but despite being strong, he's wasted countless opportunities to subdue a weaker opponent, taunted him into killing him while he himself was barely trying to kill him. I mean he's slowly strangling him while claiming that he won't stop strangling until he's dead, but he's not actually doing it. Crushing the windpipe should be very simple in that position. Instead he's given Ryuki all the time to decide to take a stab at his own neck and apparently not predicted that this would happen even though that's his whole ability.
If he dies, he gets my retarded death award. Even if these guys can reincarnate or something silly, Naidan's whole purpose is, according to the previous chapter, to test the omega's strength and weed out an omega that is too weak and unwilling to kill, but this entire fight hasn't tested a thing about the omega's strength because he's spent the entire fight, and here's my analogy, handing a knife to his opponent, guiding their hand to his neck and then repeatedly telling them to slice it and kill him. Too much needless shoehorning of the whole don't kill/kill worm thing.