Stupor

a card is discarded — 2,042 cards in the game can cause this (Stupor is one).

When a permanent makes a player discard a card thanks to Stupor:

1. Sangromancer — gains you 3 life
2. Lo and Li, Royal Advisors — puts a counter on an Advisor
3. Nath of the Gilt-Leaf — makes a token
4. Tourach, Dread Cantor — puts a +1/+1 counter on itself
5. Tinybones, Pocket Nuisance — deals 1 damage
6. Tinybones, Bauble Burglar — hits a graveyard
7. Fell Specter — makes each opponent lose 2 life
8. Spirit Cairn — makes a token
9. Confessor — gains you 1 life
10. Hostile Investigator — triggers

51 other cards care about it too. These are the ones with the most connections.

a sorcery is cast — 3,720 cards in the game can cause this (Stupor is one).

1. Spellweaver Volute — When Stupor is cast, Spellweaver Volute copies a spell
2. Lilah, Undefeated Slickshot — When Stupor is cast, Lilah, Undefeated Slickshot gets +1/+1
3. Niblis of Frost — When Stupor is cast, Niblis of Frost gets +1/+1
4. Primeval Bounty — When Stupor is cast, Primeval Bounty puts 3 counters on a creature
5. Tetsuko Umezawa, Pursuer — When Stupor is cast, Tetsuko Umezawa, Pursuer gets +1/+1
6. Thor, God of Thunder — When Stupor is cast, Thor, God of Thunder deals that spell's mana value damage
7. Krile Baldesion — When Stupor is cast, Krile Baldesion brings a card back
8. Summon: Good King Mog XII — When Stupor is cast, Summon: Good King Mog XII makes a token
9. Kykar, Wind's Fury — When Stupor is cast, Kykar, Wind's Fury makes a token
10. Blood Funnel — When Stupor is cast, Blood Funnel sacrifices a creature

424 other cards care about it too. These are the ones with the most connections.

a card in a graveyard — 7,589 cards in the game can cause this (Stupor is one).

1. Bloodbond March — Stupor puts cards into the graveyard that Bloodbond March can bring back
2. Heart-Shaped Herb — Stupor puts cards into the graveyard that Heart-Shaped Herb can bring back
3. Enlightened Confidant — Stupor puts cards into the graveyard that Enlightened Confidant can bring back
4. Tergrid, God of Fright // Tergrid's Lantern — Stupor puts cards into the graveyard that Tergrid, God of Fright // Tergrid's Lantern can bring back
5. Grazing Kelpie — Stupor puts cards into the graveyard that Grazing Kelpie can bring back
6. Dauthi Voidwalker — Cards Stupor would put into an opponent's graveyard are exiled by Dauthi Voidwalker instead, and it can play from among them
7. Endurance — Stupor puts cards into the graveyard that Endurance can bring back
8. Thieves' Guild Enforcer — Stupor fills an opponent's graveyard toward the 8 or more cards Thieves' Guild Enforcer needs
9. Soaring Thought-Thief — Stupor fills an opponent's graveyard toward the 8 or more cards Soaring Thought-Thief needs
10. Merfolk Windrobber — Stupor fills an opponent's graveyard toward the 8 or more cards Merfolk Windrobber needs

434 other cards care about it too. These are the ones with the most connections.

anything goes to a graveyard — 7,589 cards in the game can cause this (Stupor is one).

When a card hits the graveyard thanks to Stupor:

1. The Haunt of Hightower — puts a +1/+1 counter on itself
2. Duskmantle Guildmage — makes each opponent lose 1 life
3. Vulturous Zombie — puts a +1/+1 counter on itself
4. Bloodchief Ascension — makes each opponent lose 2 life
5. Compost — draws you 1 card
6. Planar Void — hits a graveyard

5 other cards care about it too. These are the ones with the most connections.

anything is cast — 31,128 cards in the game can cause this (Stupor is one).

1. Windrider Wizard — When Stupor is cast, Windrider Wizard draws you 1 card
2. Relic Amulet — When Stupor is cast, Relic Amulet puts a charge counter on itself
3. Rockslide Sorcerer — When Stupor is cast, Rockslide Sorcerer deals 1 damage
4. Umara Wizard // Umara Skyfalls — When Stupor is cast, Umara Wizard // Umara Skyfalls grants flying
5. Alania, Divergent Storm — When Stupor is cast, Alania, Divergent Storm makes an opponent draw 1 card
6. Umara Mystic — When Stupor is cast, Umara Mystic gets +2/+0
7. Master of Winds — When Stupor is cast, Master of Winds triggers

5 other cards care about it too. These are the ones with the most connections.