Here are some incentives for it: Cards like Corrupt, Cabal Coffers, Mutilate, and Defile want you to play as many swamps as possible, so their efficiency is maximized in mono-black decks
[-12]: Exile all cards from target players library, then that player shuffles their hand into their library
Other spells to consider if space can be made for them: Hardened Scales, Bow of Nylea, Song of Freyalise, Jiang Yanggu, Wildcrafter, Inscription of Abundance MrPosotive on All Will Be One 2 months ago Gearhead93 Thanks for the advice, i took out Abzan Beastmaster and a couple other odds and inns to add 3xArbor Elf, 3xUtopia Sprawl
Mayaels Aria is also worth bringing up since its the most accessible price-wise in a decade after its Surviving to Upkeep One thing you'll notice that all these cards have in common is they trigger at the beginning of your upkeep, which poses the inherent problem of projecting your win condition to the field potentially multiple turns before you can pull it off