pokemon card base set first edition Goldin [P] Psyshock (10) Flip a coin Pokemon TCG Base Set Checklist:

Youve ideally built up a big enough board or buffed your creatures enough that you no longer worry about blockers in the late game

Once per Chain, if your opponent activates a card or effect on the field (Quick Effect): You can remove 2 Advent Counters from this card and banish 2 cards from your GY with the same card type (Monster, Spell or Trap)

its definitely one of the least obvious abilities, in terms of its outward and immediate usefulness

How many times did you sleeve up something new and then have trouble sleeping the night before because you couldnt wait to unleash it on your local FNM or battle with it at a PPTQ