supporter cards pokemon tcg pocket Leaf (Mythical Island #68/86, 2-Diamonds) Supporter card (TCG) - Bulbapedia,

What is your favorite Relentless card so far

Like Creature types, the Lesson subtype doesn't have any effect on the mechanics of the card but instead allows other cards to refer to and interact with them specifically

If a spell has more than one emerge cost, you may choose to pay it for any one of those emerge costs

You get a one-time boon with "When you cast a creature spell, that creature enters the battlefield with an additional +1/+1 counter, trample counter, and vigilance counter on it." A one-time boon is a single-use triggered ability with no source

As often as you like during your turn (before your attack), you may turn all Energy attached to Charizard into Fire Energy for the rest of the turn