You can obtain the Pikachu ex (3-Stars rarity) card by opening Genetic Apex: Pikachu from Genetic Apex set
The art on a Tempest Plains is simply too gorgeous
In Blue-Red Murktide, it even helps fuel the graveyard, which allows you to play an early Murktide Regent
(I always imagine it like being what youd get if chess had certain edge cases where rooks could fly, bishops could teleport, or for a second, pawns were driving tanks.) Since the game is built around several thousand collectible cards, and almost every card has some additional unique ability to it one way or the other, it creates an endlessly manipulable, constantly surprising experience
Similarly, a deck built around very expensive spells (such as Dragons or spells like Exsanguinate with in their mana cost) will likely play powerful, expensive ramp no matter the cost of its commander