Congratulations!
To me, it seems that you're hinting towards some rain abusers (kingdra, ludicolo etc.). While it is a cool idea, I'm uncertain whether the teams would vary much, as many successful rain teams already consist of low usage mons (tornadus, said abusers).
To me, half the fun is seeing how the horses can be supported(/supporting the team) in multiple ways.
I would suggest (despite it being more fitting in autumn) the various ghosts that fall underused, such as jellicent, froslass, hoopa and even mega banette.
To me, it seems that you're hinting towards some rain abusers (kingdra, ludicolo etc.). While it is a cool idea, I'm uncertain whether the teams would vary much, as many successful rain teams already consist of low usage mons (tornadus, said abusers).
To me, half the fun is seeing how the horses can be supported(/supporting the team) in multiple ways.
I would suggest (despite it being more fitting in autumn) the various ghosts that fall underused, such as jellicent, froslass, hoopa and even mega banette.