The Master of Keys

a Horror deals combat damage — 382 cards in the game can cause this (The Master of Keys is one).

1. Captain N'ghathrod — When The Master of Keys deals combat damage, Captain N'ghathrod mills a card

a creature gets a counter — 2,691 cards in the game can cause this (The Master of Keys is one).

When The Master of Keys gets a counter:

1. Hollowmurk Siege — draws you 1 card
2. Ant-Man, Colony Commander — makes a token
3. Earth Kingdom General — gains you that much life
4. Casey Jones, Back Alley Brute — deals that much damage
5. Generous Patron — draws you 1 card
6. Shalai and Hallar — deals that much damage
7. Danny Pink — draws you 1 card
8. Enduring Scalelord — puts a +1/+1 counter on itself
9. Bold Plagiarist — puts counters on a permanent
10. Mikey & Leo, Chaos & Order — draws you 1 card

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

an enchantment is cast — 3,673 cards in the game can cause this (The Master of Keys is one).

When The Master of Keys is cast:

1. Hallowed Haunting — makes a token
2. Daxos the Returned — puts a counter on a permanent
3. Tatsunari, Toad Rider — makes a token
4. Sythis, Harvest's Hand — gains you 1 life
5. Sigil of the Empty Throne — makes a token
6. Dawnhart Geist — gains you 2 life
7. Herald of the Pantheon — gains you 1 life
8. Kami of Transience — puts a +1/+1 counter on itself
9. Argothian Enchantress — draws you 1 card
10. Mesa Enchantress — draws you 1 card

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

a nontoken enchantment enters the battlefield — 3,691 cards in the game can cause this (The Master of Keys is one).

1. Historian's Boon — When The Master of Keys enters, Historian's Boon makes a token

an enchantment enters the battlefield — 3,743 cards in the game can cause this (The Master of Keys is one).

When The Master of Keys enters:

1. Calix, Guided by Fate — puts a counter on a creature
2. Elvish Archivist — draws you 1 card
3. Victor, Valgavoth's Seneschal — surveils
4. Strength from the Fallen — gives +X/+X, where X is the number of creature cards in your graveyard
5. Doomwake Giant — shrinks a creature by -1/-1
6. Cacophony Unleashed — turns something into a creature
7. Ghostly Dancers — makes a token
8. Thassa's Devourer — mills a card
9. Killian, Decisive Mentor — taps a creature
10. Thoughtrender Lamia — makes an opponent discard a card

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

anything gets a counter — 4,415 cards in the game can cause this (The Master of Keys is one).

1. All Will Be One — When The Master of Keys gets a counter, All Will Be One deals that much damage

8 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 (The Master of Keys is one).

1. Thor, God of Thunder — The Master of Keys puts cards into the graveyard that Thor, God of Thunder can bring back
2. Samwise Gamgee — The Master of Keys puts cards into the graveyard that Samwise Gamgee can bring back
3. Bloodbond March — The Master of Keys puts cards into the graveyard that Bloodbond March can bring back
4. Gale, Waterdeep Prodigy — The Master of Keys puts cards into the graveyard that Gale, Waterdeep Prodigy can bring back
5. Harness the Storm — The Master of Keys puts cards into the graveyard that Harness the Storm can bring back
6. Transplant Theorist — The Master of Keys puts cards into the graveyard that Transplant Theorist can bring back
7. Heart-Shaped Herb — The Master of Keys puts cards into the graveyard that Heart-Shaped Herb can bring back
8. Wayward Angel — The Master of Keys fills your graveyard toward the 7 or more cards Wayward Angel needs
9. Rescue from the Underworld — The Master of Keys puts cards into the graveyard that Rescue from the Underworld can bring back
10. Sidequest: Card Collection // Magicked Card — The Master of Keys fills your graveyard toward the 8 or more cards Sidequest: Card Collection // Magicked Card 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 (The Master of Keys is one).

When a card hits the graveyard thanks to The Master of Keys:

1. Quest for Ancient Secrets — puts a quest counter on itself
2. Planar Void — hits a graveyard
3. Measure of Wickedness — gives an opponent control of itself
4. Energy Field — sacrifices itself

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

anything attacks — 17,934 cards in the game can cause this (The Master of Keys is one).

When The Master of Keys attacks:

1. Within Range — makes each opponent lose life
2. Sparring Regimen — puts a counter on a creature
3. Campsite Cuisine — sacrifices a Food
4. Obsessive Pursuit — makes you lose life
5. Invisible Woman — triggers

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

a creature is cast — 18,010 cards in the game can cause this (The Master of Keys is one).

When The Master of Keys is cast:

1. Primeval Bounty — makes a token
2. Communal Brewing — it arrives with counters thanks to Communal Brewing

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

a creature enters the battlefield — 19,800 cards in the game can cause this (The Master of Keys is one).

When The Master of Keys enters:

1. Scurry Oak — puts a counter on itself
2. Fathom Mage — puts a counter on itself
3. Pollywog Prodigy — puts a counter on itself
4. Airbender Ascension — puts a quest counter on itself
5. Lonis, Genetics Expert — puts a counter on itself

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

anything enters the battlefield — 26,499 cards in the game can cause this (The Master of Keys is one).

1. Prowl, Stoic Strategist // Prowl, Pursuit Vehicle — When The Master of Keys enters, Prowl, Stoic Strategist // Prowl, Pursuit Vehicle puts a +1/+1 counter on itself

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