If a Flying-type terastalizes into Stellar, will it still be unnafected by Terrain-Based effects?

Question

If, for example, a Kilowattrel terastalizes into Stellar, and its opponent Azumarill uses Aqua Jet on it while Psychic Terrain is up, will the Kilowattrel be hit by it or not?

Answer 1

It will be hit, because the Pokemon is immune to Ground, so it isn't grounded.

Source

Comments

Thanks.