I don't buy that Robin will effectively use invisiblity. Irregardless of him "building a narrative" for the Teen Titans, "he's competitive" doesn't overcome the fact that he consistently fights while visible.
However, I also don't buy that Major reliably chooses to turn invisible and run away to get a gun before Robin can engage in melee, where he can effectively put her down by hitting hard. Major just doesn't have the demonstrated durability or general physicals to survive an encounter with Robin.
Winner:
Robin / Wolf
Dracula's strikes are consistenly bad compared to what Ohma takes, whether it's due to weakness or "holding back" does't matter. Ohma, however, can output at a level Dracula can't really take, and has the added benefit of much greater skill. Ohma has insurmountable advantages in melee.
Dracula might have some vague idea that Ohma is a particularly dangerous human—though "if Dracula were a Kengan character he'd be attuned to this stuff" is a fake-ass argument; Dracula isn't a Kengan character, and speculation on how something might be written is very much a "Saitama one punches anyone because that's how he'd be written in One Punch Man"-level argument—but that doesn't mean he's going to become hyper-cautious in-character, or be able to implement a win condition without entering melee and getting mogged.
Winner:
Ohma / Kirbin
The gap between Kuroki's demonstrated striking and Batman's demonstrated durability is such that if Kuroki strikes Batman's head, Batman no longer has a head. Even if he opens with a "piercing blow", I see no reason Batman's head would neccesarily survive in whatever vague level of operability it requires for him to remain alive. Having a knife poke his brain isn't the same as having a hand-shaped hole put through it. Both debaters present a head strike as a reasonable opening move for Kuroki.
If Batman kites and tosses a batarang into Kuroki, there's a good chance it's lethal because it's sharp. However, there's not really anything to assert that this is an in-character opening move. Batman seems to consistently run into melee in the provided scans, only demonstrating some degree of caution against Dracula, and still opening that fight with melee.
Batman's talons and teeth provide an effective win condition in melee, and he ostensibly has the speed to deliver on it before Kuroki can deliver on his own win condition, but a combination of Batman's sometimes less-than-immediate responses to attacks and Kuroki's martial skill complicates this greatly.
Winner:
Kuroki / Kirbin