In the case of the former, its because the best choices vary not only by color identity, but often by specific deck building limitations: Seismic Assault and many other red effects want you to play an extra-high land count, while a black deck with reanimation and Tortured Existence obviously cares about discarding creatures
Mimikyu is a ghost Pokemon that wears a bag on its head which has Pikachus face drawn on it, like a mask
Card not found from Legions (2003) is an interesting tribal card in that its actually worse when you have more of its brethren
This is because, if you've dealt combat damage to a player with the Hope of Ghirapur, it can be sacrificed, preventing that player from casting noncreature spells until your next turn, causing serious headaches for any deck that revolves around any card type besides creatures
With that said, here are all the reprints
Made with a soft fabric top to reduce damage to cards during play and a non-slip rubber backing to keep the playmat from shifting during use, playmats enha