Weavile SW and Shaymin(Land Form) PT

[ApachePrime]

Hey guys quick question:
If I have an active grass pokemon, lets say Cherrim, with 90 damage on it. I also have out a Shaymin Lvl X so the Cherrim has 120 HP. If I use Dark Engage and turn Cherrim dark, would I be knocking out my own pokemon? Would Cherrim lose the benefits of being a grass pokemon, such as Wild Growth or Thankfulness?

Thanks for your time.

 

[PokePop]

A Grass Pokemon that turns to the Dark Side will lose all benefits of the Green.

Don't give in to your anger, Luke.