The more I think about it, the more I realize that people are in denial about Decidueye being in Smash.
>Greninja aka Water Starter introduced in Smash 4
>Charizard return with Mega Charizard X as a Final Smash in Smash 4, Fire Starter
But we have yet to get a fresh Grass starter, and that's where either Decidueye or Sceptile come in. Decid would have a unique moveset, and Sceptile would basically be a Grass Greninja with a Mega for it's Final Smash.