Personally, I prefer a setting where the PCs are humans, or humanoid, but a PMD style thing would be pretty cool, especially since I think WAR has pretty much always focused on human/humanoid characters. As for genre, fantasy - especially urban fantasy - is my absolute jam, although I'm not opposed to focusing on sci-fi or putting a bit of it in the mix.

This is a bit cliche, but maybe every group is assigned a patron Legendary Pokemon? A group with a mischief-making prankster motif might have Hoopa; a group with a slow-and-steady strategy might have Regigigas or Groudon; a very "edgy" group might have Necrozma or Yveltal. These legends could be fighting - maybe because being gods is hard, or maybe because of some outside influence. Different allegiances could be made, but each group's Legendary representative would have their own agenda. There's also possibilities to be found in a post-apocalypse world - maybe humans have vanished and Pokemon are left to figure out what to do with themselves, forming into groups based on what kind of past involvement they had with humans; maybe the world is under the thumb of a horrifying dictator of some sort and each team is forming their own reaction faction. I have a jillion tiny plot bunny ideas; if you want a hand coming up with premises, I wouldn't mind helping helping brainstorm/being a sounding board.

I do have some concerns about activity, though. I know that the nature of this event means that high activity is a necessity, but some people on here can churn out four posts a day, and others are lucky if they can make one post a week. I remember some WARs got really rough because the high-activity people would often make game-changing posts, forcing those of us who couldn't go as quickly to adjust and take even more time, during which more people would shake things up even more, etc. Do you have any plans for how to handle posting order, a post throttle, or anything like that?