[@Midnight Howl]

We could add the Queen of Hearts to the Wonderlanders?

Have her be a separate power that assists the Red King now and then? Or maybe she tries to but both sides can't stand her rule and will keep her out of both their lands?

I don't know. Just throwing out suggestions. 

Or maybe she was in Wonderland but the two Kings got tired of her games and hopes of ruling Wonderland or heck even trying to seduce them and then ended up being banished or push back by the armies?