Given that the faction war is over, cross-faction grouping is a thing, and the prevalence of free-for-all pvp quests, I think we need a new Censer of Agony/Sliver of N’Zoth type toy.
Instead of just limiting it to just one zone though, have it work everywhere (except sanctuaries perhaps…), so it can be an evergreen thing. That the previous versions only worked in certain zones was awkward because the zone limits made it easy to forget it existed, while simultaneously making the zones it did work in a mess.
Were it to work in more places, it would spread out the chaos a bit, and allow groups of villains/outlaws/whatever to form more organically.
Plus, a third virtual faction could help take the edge off of lopsided shards. Like, if there’s 3 Alliance in a zone for every Horde (basically every Tuesday…), some of us could go hostile to turn it into a 3-way fight.
To make it more interesting, maybe swap our skins to the villain version of each race where applicable? For instance, maybe Draenei could swap to the red Man’ari eredar skin while active, Moose Tauren could turn into Feltotem, or Gnomes become Leper Gnomes. This would give us a chance to play sub-races which would likely never become playable.
As for the races with no obvious “evil twin,” could just change the mouseover tag to a different group? EG, humans might show as Defias, or undead might be tagged as Scourge.
Might not make sense lore-wise for, say, Fel Orcs to be running around Dragon Isles. But neither does Night Elves fighting Worgen over ducks.