....man THAT'S HARD TO PICK. Short of Arceus though (which might not be the best choice ANYWAY given Sion and godlike-types) it'd be a tough choice between Kyurem and Ho-Oh or maaaaybe Giratina. Ho-Oh for reasons you already know- it's a freaking PHOENIX and is big and powerful and looks cool and would generally be a valuable and highly visible ally- plus it's native to Johto. Kyurem... you also know why, and it'd be for the hilarious canon parallel thing going on. Giratina would be for similar reasons to Kyurem, plus the whole just being the antithesis of the normal world, which really sounds a lot like the Hero there in a way.

ULTIMATELY THOUGH probably Ho-Oh because it's the most IC option for him to pursue and phoenixes have an association with royalty. Even though the other two are technically part dragon type they don't really LOOK it so.

So we have a title and a cover for the next volume of canon, what do YOU think is going to happen next?