The visits to the plane of Ixalan gave us a lot of modern pirate options and subsequent set releases have added plenty more swash-buckling, one-eyed, hat-wearing goodies to the seas they roam and villages they plunder
Once upon a time, Pokmon cards were a pure thing
That permanent gains haste, "When this permanent leaves the battlefield, it deals damage equal to its mana value to each creature," and "At the beginning of your end step, sacrifice this permanent." If a permanent has in its mana cost, X is 0 for the purpose of determining its mana value
Keep in mind that the codes for older sets, like Throne of Eldraine, Theros: Beyond Death, and Ikoria: Lair of Behemoths, will become invalid at some point in the future
Greven prompts you to sacrifice creatures to draw cards, and Chainer allows you to cast creatures from your graveyard