Mephitic Vapors {2}{B}
Sorcery
All creatures get -1/-1 until end of turn.
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.)
click a line to search just that ability, click more to combine them
Cards that do something similar expected a card that isn't here?
Reports become test cases the matcher is graded against before an update ships. Delvefall isn't a chatbot guessing, it compares the printed rules text of every card with plain math, and examples like yours decide which differences should count.
Glistening Deluge 97%
$0.26#20465
"All creatures get -1/-1 until end of turn. Creatures that are green and/or white get an additional -2/-2 until end of turn."
Deluge of Doom 96%
$0.26#10019
"All creatures get -X/-X until end of turn, where X is the number of card types among cards in your graveyard."
Feast of Succession 95%
$0.26#14588
"All creatures get -4/-4 until end of turn. You become the monarch."
Cloudkill 94%
$0.22#15689
"All creatures get -X/-X until end of turn, where X is the greatest mana value of a commander you own on the battlefield or in the command zone."
Terror Tide 94%
$0.28#6464
"All creatures get -X/-X until end of turn, where X is the number of permanent cards in your graveyard."