I think this is a nice balance of what we're trying to achieve, but here are options as I see them
For the rest of the match, your goal should be stacking energy on your Gastly and trying to draw out Mega Gengar EX
At the end of the day its generally best to just look up legality on scryfall if you have any questions, and theres always the possibility that theres an exception to a rule explained above
It also lets you play lands untapped on your opponents turn which can help with playing cheap removal spells on recent targets
What Happens When You Counter an Activated Ability
The past expansions of Pokemon TCG Pocket include Mythical Island , which introduced new cards with a focus on rare Pokemon, PROMO-A offered special promotional content, and Genetic Apex , which highlighted genetically altered Pokemon