duskmourn mtg cards preview at Polygon include a nasty little blue book built around the sinister color combination of Black and Green Fear of Infinity | Duskmourn:

This deck will keep you one step ahead of your opponent and help you stand strong in the face of challenges

Do you know what else is one-of-a-kind

Its especially powerful with cards that have an additional downside to cast, like discarding a card or losing life

However, when its a creature, if it would deal combat damage to a creature, it instead makes it so that the owner has to shuffle that creature back into their library

This gave the players who discovered the quasi-glitch in Magic Online a massive advantage by activating the Grim Monolith's companion abilities that do not untap in the untap phase

Angel decks stabilize faster and pressure opponents through large life swings rather than raw speed