[Googi]

Really, even if it's given a name it won't necessarily by widely used (the Northwest mountain is named "Mount Antora" but nobody calls it that anymore.)

But if it's going to be named, I'll back "Kaimetsu" as well. Although being that strictly speaking, "Kaimetsu" means "destruction", something like "Kaimetsu Island" might be better suited to the so-called "Battle Island".