booster box of ixalan Rivals Pack 3–7 Uncommon The Lost Caverns of Ixalan

Its ability to return from the graveyard means most removal is just a speed bump

At the start of the Damage Step, if this card attacks a face-down Defense Position monster: Destroy that monster, and if you do, inflict 1000 damage to your opponent

It's absolutely great at placing +1/+1 counters on creatures when casting a card from exile

Though that is a small price to pay for a free monster that can be used in countless other capacities.

Like most Pokmon cards, the value of Greninja depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (SWSH Black Star Promos)

The Iono Special Illustration Rare is the most sought-after Trainer card in the set