I'm actually a little unsure if it'd have to absorb Xerneas and Yveltal, mainly because they've done the legendary absorption thing with Kyurem. Wouldn't it be a little redundant?

Probably just absorbing their energy, not absorbing the Pokémon themselves.

It might just drain their energy and revert them back to their cocoon and tree forms.

For me the Fenrir connection is a little bit dubious, because Fenrir is not usually associated with Yggdrasil.

Hel I think is a better fit. Mythology usually depicts Hel as having an appearance of two halves, with some depictions of her representing half corpse and half alive (if I know it correctly). This shows a little bit in the Perfect Form, with the red and blue sides. Red and Blue could represent Yveltal and Xerneas, respectively, who represent death and life.

:lol

I think my problem with Hel is that it's usually a noticeable difference between the two sides, which is why for Zygarde's connection to Hel being a couple of blue and red highlights is hard for me to swallow.
I could be entirely wrong, though...

Yeah, if it is a reference, it's not a very explicit one. Still, it's enough for me to buy it. :lol

I think Zygarde Perfect looks pretty cool, and I'm interested to see how this Zygarde percentage thing is gonna factor into any sort of story.

I want an action figure or statue of Zygarde perfect on my shelf, it is such a cool design. :lol

Zygarde Perfect Amiibo. Not coming to a store near you!