What would happen if Trolls had blood transfusions? Like a Purple-blood giving his blood to a Gold-blood because the Gold-blood has not enough blood? On a further note, what would happen if two trolls of contrasting blood colour have an offspring?

I do not quite think it’d be healthy for those Trolls, if their bodies don’t outright reject other caste’s bloods, I bet there’d be some awful consequences. Human Blood has a few different types that can FUCK you up if you’re not careful with transfusions, I can’t even imagine with the more volatile-seeming genetics of Trolls and the visibly-distinct blood colors, it’d be very much the same.

That being said, that’s simply not something that happens as far as we know about Troll Anatomy. Rather than having a couple mix their genetic material, it seems One Troll’s Genes predominate over the rest- And I say rest because, remember, Troll Reproduction isn’t a matter of two Trolls, it’s like. All of Alternia’s genetic pool dumped into a big, gross bug and mixed to lay thousands of eggs. “Incestuous Slurry” is the canonical term for a reason. Troll Reproduction is weird.