Idunno which I'd like him to pick up more, The Dragon Prince or Ben10. On one hand, Gwen is hot. On the other, she's overdone, and Rayla (that's the elf's name, right? Haven't seen the series. Yet. Done by Avatar's creator, so I shall.) is equally so, and more or less unique as far as trainer games go, I think. I mean, we get lots of drow-style dark elves, lots of wood elves, lots of anime-style dark elves (chocolate elves), but not many, if any, pink-purple night elf esque elves (I know she's not, but her skintone is similar), at least in Trainers. Though theres that one rogue hall trainer game that's scheduled to get Tyrande as a side character, so...
I actually doubt he's gonna do a giant crossover thing like he's currently got; I think he's only doing it for a showcase of possibilities.
Also, I don't think Dragon Prince style is too far off from his Avatar game's style, so...