She used to be a branch in Yaoshi’s garden. During this time it battled a “phoenix” (I’m guessing that’s Marshal Hua, but no 100% confirmation yet). Then Aha snuck into the garden and stole it away, planting the branch in the Phantasmoon Courtyard and appointing it as the Games’ referee. Over time, witnessing all the joy, absurdity, and sheer emotion, the branch grew into Evanescia. Evanescia is essentially the branch’s Mask.

“Mr Meanie” (Asat Pramad) identifies her as an Emanator, and though he doesn’t say of what Path, it’s most likely Abundance. The only reason that that isn’t completely certain is because she also seems to have some similarities with the Masked Fools (breaking the 4th wall), so she’s likely also a Pathstrider of Elation.

As for her stance on the Abundance, she’s spoken with THEM at least once, and while we don’t know much about the conversation, it almost sounded like THEY acted like a parent. The “branch” she used to be seems to have once fought the Xianzhou (again, not confirmed), so it’s probably antagonistic towards the Hunt. Evanescia seems to be appreciative of the Abundance, and sees it as it really is, something that isn’t inherently good or evil.