japanese 25th booster box One Piece EB-02 Anime Collection Pack (Japanese) 02] includes many ways to strengthen Leaders from past packs (1 Pack) Pokemon Card Game

Quick Sliver Surprise Slivers Secret Lair Bonus Sheet Market Price: $149.85 2003s Legions , from the Onslaught block, produced a number of memorable Slivers including this two-mana green one that grants all Sliver cards (not just your own) the flash keyword

8 Omnimon Alter-S (Alternate Art) Market Price: $37.16 If Agumon is the Pikachu equivalent in Digimon, then Omnimon is the Charizard

Scroll down to the support section to find them

In EDH it's impossible to play a 200+ card deck due to the rules of the format, but in its Standard format, Battle of Wits decks were somewhat competitive

See the Keras documentation, and also this example, for details