Getting foils to pimp my deck, a complete set of a particular edition of a card, even going so wild as to get all my lands with the same art for the sake of symmetry
All legendary Slivers are multicolored (with all five colors), allowing you to access all Slivers
If you're casting an adventurer card or split card with escape, you choose how you wish to cast it, then pay the appropriate cost (for the Adventure, the creature, or the half of the split card you chose) plus exiling three cards
The spoiler from that story is Bloodhall Priest, a vampire who deals two damage to target creature or player, but with some conditions
Corrupt counts any land you control with the subtype Swamp, not just ones named Swamp
Also placed in for good measure and strategy are Colorless and Darkness types such as Pancham, Scraggy, and Lickilicky