Ko is a vampire just like Mikaela but the difference in skill is considerable. Ko tends to run out of stamina quickly and hasn’t had time to unleash a flurry of feats the way that Mikaela has. At this point in time, Ko’s best bet would be a sequel series to close the gap. He just wasn’t able to be nearly as interesting as Mikaela either. At least Mikaela had a firm goal of saving Yu. Ko didn’t really seem to have an end game objective which didn’t help matters in terms of finding a reason to gain strength. Mikaela wins.