"I guess we know from where the Netherese shadow magic is coming from now..."
The tadpole tampering seems to be a more recent event. If there is a source of the shadow magic at moonrise towers it makes sense for someone to go there and exploit it. Why don't the tadpoles need to eat? Something must power them. We know that humanoids can be sustained by big ion stones, maybe the same works for splinters and tadpoles.
I sometimes use thought experiments. I don't necessarily believe in every idea I post for discussion on this forum