This is a neat card, but it's unfortunately coming in at a bad time.
The Solgaleo deck is currently getting the most hype, and Solgaleo resists Psychic.
Lunala is also weak to Darkness, and Zoroark GX is starting to pick up steam.
The 2nd attack is very interesting, but once again if Solgaleo really does become one of the most popular decks when we get Ultra Prism, the fact that the SuMo Solgaleo GX discards energy on attack makes it pretty underwhelming. Even in the mirror match where the new Lunala GX discards 2 energy, Turtonator GX discards energy, Bulu discards energy, and Alolan Ninetales GX discards energy.
Great card when you put it in a vacuum, but it will likely be not good due to the anticipated meta.
But let's not be a downer about this. These new prism star Pokemon are neat and I like the mechanic.
Part of me thinks that one of the reasons why they're forcing these cards to be 1 ofs is to make Gladion more playable in the future when Prism Star Pokemon become the primary tech option in most decks and you don't want them to be stuck in your prizes. But maybe I'm just crazy.