>>28503917>Zygarde didnt interfere with Primals because the Earth was reshaping itself; the environment wasnt in danger. Only life on it.That's what I though. Magma/Aqua's should affect the overall proportion of the landbased versus water based ecosystem but not exactly the ecosystem itself and same goes for Xerneas/Yvetal whereas the UBs represent a direct threat to both living beings as well as the underlying environment which supports them.
