In deck switch Green this shouldnt be too much an issue, but this card wont go in every deck
If you somehow can't discard a card (probably because you had no cards in hand and another effect prevented you from drawing cards), you won't put any counters on Cait no matter whether or not the defending player discarded a card or what that card's mana value is
More characters, items, locations, and lore flesh out the Lorcana universe
Hopefully you were super prompt picking up your upgrades for that Commander deck
Mizzix of the Izmagnus, the new Gandalf the Grey or Saruman, the White Hand, Niv-Mizzet, Parun and his counterparts, etc.) or Burn spells (Solphim, Mayhem Dominus, Urabrask // The Great Work, Aegar, the Freezing Flame, etc.), odds are Immolating Gyre will have plenty of cards to count by the time you hit six-mana
That's how I feel about Unhinged