Guilds of Ravnica

Mission Briefing | Instant | | Surveil 2, then choose an instant or sorcery card in your graveyard. You may cast it this turn. If that spell would be put into your graveyard, exile it instead. (To surveil 2, look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.) | Matt Stewart

Mausoleum Secrets | Instant | | Undergrowth — Search your library for a black card with mana value less than or equal to the number of creature cards in your graveyard, reveal it, put it into your hand, then shuffle. | Adam Paquette

Response | Instant | | Response deals 5 damage to target attacking or blocking creature. | Daarken

Assure | Instant | | Put a +1/+1 counter on target creature. That creature gains indestructible until end of turn. | Jason A. Engle

Expansion | Instant | | Copy target instant or sorcery spell with mana value 4 or less. You may choose new targets for the copy. | Deruchenko Alexander

Assassin's Trophy | Instant | | Destroy target permanent an opponent controls. Its controller may search their library for a basic land card, put it onto the battlefield, then shuffle. | Seb McKinnon