Bat Creatures: If the Alpha dies, maybe the remaining males compete to become the next Alpha? There would be physical changes but their biology is already weird. Also, the females probably concentrate mana in themselves, to help fuel their biology including imbuing eggs with it. Maybe they recover MP on the fly similar to HP regeneration. Helps explain why they're so good as sacrifices, and why vampires find them tasty despite being further from human than even dwarves.I'm bored & got nothing to do... I'm gonna write my theories on the Ancients & their experiment on here. Feel free to read & debate or ignore
Elves: Seem to be uniformly hedonistic, leading to a lot of breeding, a major negative despite their physical appearance and long lives. Maybe Elves were a promising experiment but they just couldn't eliminate the hedonism.
Vampires: I can also see the Ancients viewing the strong tendency for egotism/sollipsism as a big negative. I can't imagine no one thought of sunblock, perhaps it's still not enough to protect a full-on vampire.