Mime was tantamount to saying you lose to major tournament decks such as Rain Dance
Then, after youve cast it, unlike other powerful recursion spells (Nostalgic Dreams, All Suns' Dawn, etc.), it doesnt self-exile, but instead, heads to the bottom of your library for another dose of power
ST14 3D2Y Black Monkey D.Luffy shiened a couple of weeks after his release, but quickly fell off, and with the ban of Gecko Moria, the Leader sees no play anymore
Deeproot Waters
Besides having been created by Pokemon legend James Turner, Pikachu ex getting included in this set at all is an obvious nod to one of the greatest cards in the Scarlet and Violet era
Combine the -1/-1 counters with cards like Glissa Sunslayer (First Strike, Death Touch), and Massacre Girl, Known Killer (Gives all your creatures Wither), and some big creatures (Grave Titan, The Scorpion God, and Carnifex Demon), and you can amass a pretty impressive army in short order