Worldpurge

Return all permanents to their owners' hands. Each player chooses up to seven cards in their hand, then shuffles the rest into their library. Each player loses all unspent mana.

Narset, Enlightened Master

First strike, hexproof
Whenever Narset attacks, exile the top four cards of your library. Until end of turn, you may cast noncreature spells from among those cards without paying their mana costs.

Reverse the Sands

Redistribute any number of players' life totals. (Each of those players gets one life total back.)

Dimensional Breach

Exile all permanents. For as long as any of those cards remain exiled, at the beginning of each player's upkeep, that player returns one of the exiled cards they own to the battlefield.

Sway of the Stars

Each player shuffles their hand, graveyard, and all permanents they own into their library, then draws seven cards. Each player's life total becomes 7.

Worldfire

Exile all permanents. Exile all cards from all hands and graveyards. Each player's life total becomes 1.