Farewell gives white decks a broad battlefield reset with the flexibility to choose which categories it affects. For six mana, you can exile artifacts, creatures, enchantments, graveyards, or any combination of those groups, making it useful when several kinds of engines are developing at once.
The exile effect removes indestructible permanents and prevents creatures from generating ordinary dies triggers. That can make it especially effective against sacrifice decks relying on Blood Artist or recursion through cards such as Reanimate. Choosing graveyards as well can remove the resources those decks intended to use for rebuilding.
The modes affect your cards too, so select them around your own position. A deck with valuable enchantments may choose creatures and artifacts while keeping its enchantment engines. Teferi’s Protection can phase out your permanents before Farewell resolves, preserving your battlefield through the selected modes, although an exiled graveyard is not protected by phasing your permanents.
Six mana is a significant investment, and leaving opponents’ lands available means they can rebuild quickly. Farewell also does not normally remove planeswalkers unless they fall into another chosen category, leaving some threats outside its reach. Keep cheaper interaction such as Swords to Plowshares for the turns before a reset is affordable. Farewell works best when its selected modes remove several opposing advantages at once and your deck has a practical way to develop afterward, rather than simply clearing everything because all four options are available.
