Chancellor of the Annex 
Creature — Phyrexian Angel
$2.86 #10169 0.80 15.3 years
You may reveal this card from your opening hand. If you do, when each opponent casts their first spell of the game, counter that spell unless that player pays 
.
.Flying
Whenever an opponent casts a spell, counter it unless that player pays .
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Nether Void96%
$519.01↑#16171↓2.23↑32.3 years↑
"Whenever a player casts a spell, counter it unless that player pays 
."
."
In the Eye of Chaos86%
$193.45↑#21265↓1.30↑32.3 years↑
"Whenever a player casts an instant spell, counter it unless that player pays 
, where X is its mana value."
, where X is its mana value."
Cephalid Shrine86%
$0.29↓#30163↓0.44↓24.9 years↑
"Whenever a player casts a spell, counter that spell unless that player pays , where X is the number of cards in all graveyards with the same name as the spell."
, where X is the number of cards in all graveyards with the same name as the spell."
Shimmering Glasskite86%
$0.13↓#30656↓0.12↓21.6 years↑
"Flying"
Ice Cave84%
$0.77↓#21126↓0.92↑25.3 years↑
"Whenever a player casts a spell, any other player may pay that spell's mana cost. If a player does, counter the spell."
Planar Chaos81%
$2.31↓#7147↑1.41↑24.3 years↑
"Whenever a player casts a spell, that player flips a coin. If they lose the flip, counter that spell."
Decree of Silence81%
$29.75↑#115141.15↑23.3 years↑
"Whenever an opponent casts a spell, counter that spell and put a depletion counter on this enchantment. If there are three or more depletion counters on this enchantment, sacrifice it."
+1 more matching line
Lunar Force80%
$0.25↓#21116↓0.22↓10.1 years↓
"When an opponent casts a spell, sacrifice this enchantment and counter that spell."
Disruptive Student80%
$0.21↓#20535↓0.14↓27.9 years↑
"
: Counter target spell unless its controller pays ."
: Counter target spell unless its controller pays ."
Vodalian Mage79%
$0.14↓#23508↓0.33↓31.8 years↑
"
, : Counter target spell unless its controller pays ."
, : Counter target spell unless its controller pays ."
Chalice of the Void78%
$16.39↑#92681.14↑22.9 years↑
"Whenever a player casts a spell with mana value equal to the number of charge counters on this artifact, counter that spell."
Disruptive Pitmage77%
$0.15↓#17667↓0.15↓23.9 years↑
": Counter target spell unless its controller pays ."
: Counter target spell unless its controller pays ."
Soul Barrier77%
$0.29↓#17733↓0.55↓31.3 years↑
"Whenever an opponent casts a creature spell, this enchantment deals 2 damage to that player unless they pay 
."
."
Jace, Unraveler of Secrets77%
$1.37↓#6632↑0.7310.4 years↓
"−8: You get an emblem with "Whenever an opponent casts their first spell each turn, counter that spell.""
Counterbalance76%
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"Whenever an opponent casts a spell, you may reveal the top card of your library. If you do, counter that spell if it has the same mana value as the revealed card."
Isolation Cell76%
$0.31↓#12534↓0.55↓15.3 years
"Whenever an opponent casts a creature spell, that player loses 2 life unless they pay ."
."
Swindler's Scheme75%
$0.16↓#23086↓0.21↓4.4 years↓
"Whenever an opponent casts a spell from their hand, you may reveal the top card of your library. If it shares a card type with that spell, counter that spell and that opponent may cast the revealed card without paying its mana cost."
Rhystic Study74%
$66.79↑#44↑2.73↑26.3 years↑
"Whenever an opponent casts a spell, you may draw a card unless that player pays ."
."
Lavinia, Azorius Renegade74%
$0.18↓#3183↑0.91↑7.6 years↓
"Whenever an opponent casts a spell, if no mana was spent to cast it, counter that spell."
Boromir, Warden of the Tower74%
$6.61↑#851↑0.60↓3.2 years↓
"Whenever an opponent casts a spell, if no mana was spent to cast it, counter that spell."