According to the translation offered by Bulbapedia, the ability "mortal shuriken" allows Greninja's controller to discard a water energy from their hand, once per turn, to deal sixty damage to any of their opponent's Pokmon
This Pokmon is often found in regions like Johto and has appeared in games such as Pokmon Gold, Silver, and Crystal, as well as their remakes, HeartGold and SoulSilver
The Fusion Strike Booster Pack offers alternate art pieces for Sword and Shield cards, making it a great opportunity for any collector
The most commonly held argument is that of Promissory Estoppel, which, in massively reductive terms, says a promise can be legally binding, even if there was originally no legal declaration or intent