Poison/Dragon please. I don't care whether it's a legendary or a psuedo, I just want it.
Hopefully it'll be another Hydra. A "true" Hydra this time.
I liked the idea of Hydreigon gaining an ability, that, when Honedge attacked it, Hydreigon's attack stat is boosted (growing more heads). Obviously, it probably wouldn't work, but it's fun to think about.
Fighting and Dragon types are ruling the meta. Fairy is being added to help balance this and Poison will be counter Fairy as well as keep its natural defense to fighting. Poison is already a viable type and it's getting a boost.