I am glad that USEC has taken over the argueing, because at this point it has become so stupid that even I do not have the stamina to argue against Sanure. Either Sanure is a very dedicated troll, or he is both unable and unwilling to understand what any of us mean.
I will sum up my opinion on this in 3 short points, and then never acknowledge Seras again.
1) Unless you are serious about debuffing Seras as a mean to make her balanced, dont even try to. "She heals a bit less under sunlight" is not a flaw, and "she takes all the damage of those around her and dies instantly" is just a joke. You basicaly have 2 ways. One, make it 50/50. During night, Seras is overpowered as heck, during day, she becomes underpowered as heck - all the perks turn to the direct opposite. This is literaly the easiest and most fair way to balance her out, yet allow her to be overpowered. Two, remove all the perks except your favourite one.
2)Differentiating and making characters original does not happen in abilities alone. Kyle, Icarus and Hilda are all radicaly different from eachother, in the way they are *outside* of combat, and that is what matters. This matters so much, it is almost irrelevant to explain, as USEC tried times and times again despite your selective deafness, that they are different inside of combat too, and not by a small stretch. I can see how hard it is to make a character directly copypasted from an anime in any way original, but if achieving the uniqueness by "Seras is the only character that is massively overpowered", then maybe you should just stick with Sen, or some of the other quite unique characters that never even got introduced.
3)Seras is in almost no way designed to be a character of this game. Sadly, I am not the GM, and as such I can't just put a big "denied" stamp on her forehead, but in any part of the game I can controle, I will do so. It's not even too heavy against the lore, the existance of parallel worlds is a thing. I hereby declare that anything under my controle exists in a reality that does not Include Seras existance. It pays little difference if in world the northsdale five just took down Selkhim on their own, or if in world omega there was a scenario where some OP vampire was also throwing in her five cents. Seras is disturbing my enjoyment of this game so much, that I refuse to play a part in your enjoyment of this game through seras