Vexing Bauble {1}
Artifact
Whenever a player casts a spell, if no mana was spent to cast it, counter that spell.
{1}, {T}, Sacrifice this artifact: Draw a card.
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.
Void Mirror 98%
$0.32#15339
"Whenever a player casts a spell, if no colored mana was spent to cast it, counter that spell."
Ice Cave 94%
$0.80#20895
"Whenever a player casts a spell, any other player may pay that spell's mana cost. If a player does, counter the spell."
Dovescape 93%
$4.38#11894
"Whenever a player casts a noncreature spell, counter that spell. That player creates X 1/1 white and blue Bird creature tokens with flying, where X is the spell's mana value."
Cephalid Shrine 91%
$0.29#29975
"Whenever a player casts a spell, counter that spell unless that player pays {X}, where X is the number of cards in all graveyards with the same name as the spell."
Bazaar of Wonders 91%
$2.78#28053
"Whenever a player casts a spell, counter it if a card with the same name is in a graveyard or a nontoken permanent with the same name is on the battlefield."
Lavinia, Azorius Renegade 88%
$0.51#3154
"Whenever an opponent casts a spell, if no mana was spent to cast it, counter that spell."
Boromir, Warden of the Tower 88%
$5.62#837
"Whenever an opponent casts a spell, if no mana was spent to cast it, counter that spell."
Liberty Prime, Recharged 87%
#7479
"{2}, {T}, Sacrifice an artifact: You get {E}{E} and draw a card."
Planar Chaos 84%
$2.25#7067
"Whenever a player casts a spell, that player flips a coin. If they lose the flip, counter that spell."
In the Eye of Chaos 84%
#21143
"Whenever a player casts an instant spell, counter it unless that player pays {X}, where X is its mana value."