RE: Avatars and Art v.2. Read the rules. Reshiram v.Z, Zekrom v.R added.
To DNA: If you wanted to do that with full body art, you'd need to ask permission first. Basically, doing anything with the avatars or art other than just using one of the avatars as-is requires permission first.
As far as Darmanitan Zen Mode goes, I was actually going to draw it the other day. Since Sugimori doesn't have artwork for it (at least not that I've seen), I figured people would appreciate at least having my art to use. It's definitely something I'll be making in the near future.
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Added Reshiram v.Z and Zekrom v.R to the thread. In case it wasn't immediately apparent, the "Z" and "R" stand for Zekrom and Reshiram, respectively, since the two Pokémon are drawn in their counterpart's colors. I know it's cliché, but it was fun nonetheless.