Mewtwo-GX is interesting. Yes, it only can do 60 damage for 2 Energy and yes, Espeon/Garbodor is a thing, but it can hit Weakness numbers pretty easily.
Garbodor: 2 Energy or 1 Energy + FFB + Kukui
Espeon-GX: 3 Energy + FFB/Choice Band/Kukui or 2 Energy + Choice Band + Kukui
All you need to do is hit one Max Elixir, and you can sweep that deck. Against most other decks, it doesn't have the high damage output to keep up with most decks; akin to Tauros-GX. It might be a cool partner with Lunala-GX especially with Mewtwo's GX attack.
190 HP is solid and can tank a Drampa-GX and most other decks. Weakness Policy/FFB can help it survive longer but, it seems like an uphill battle. The Weakness is an absolute pain. Unless there is a Pokemon that removes Psychic Weakness or Dimension Valley-esque effect gets printed, this will likely be a fun card in a fun deck.