I'd like to vote Zebstrika for Mid tier.
I used one in-game for fun in my last run-through. It comes right before Skyla, which is amazing because it can get great grinding against her team and gym. It can help a bit throughout the next part of the game, and even gets Flame Charge to help deal with the bountiful Grass types. It can also help substantially with Marlon's gym, and really just destroys any Flying-type or Water-type which you encounter.
Why Mid? It still only comes fairly late game, and it's attacking stats can be lacking. Additionally, most Ground moves just tear it apart.
EDIT: Also agreeing with above post - Panpour Mid, Pansage Low, and Pansear Low as well.
I used one in-game for fun in my last run-through. It comes right before Skyla, which is amazing because it can get great grinding against her team and gym. It can help a bit throughout the next part of the game, and even gets Flame Charge to help deal with the bountiful Grass types. It can also help substantially with Marlon's gym, and really just destroys any Flying-type or Water-type which you encounter.
Why Mid? It still only comes fairly late game, and it's attacking stats can be lacking. Additionally, most Ground moves just tear it apart.
EDIT: Also agreeing with above post - Panpour Mid, Pansage Low, and Pansear Low as well.