The Master of Keys

a Horror deals combat damage — 285 cards in The Master of Keys's colors 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 — 1,290 cards in The Master of Keys's colors can cause this (The Master of Keys is one).

When The Master of Keys gets a counter:

1. Danny Pink — draws you 1 card
2. Bold Plagiarist — puts counters on a permanent
3. Omarthis, Ghostfire Initiate — puts a counter on a permanent
4. Rikku, Resourceful Guardian — triggers

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

an enchantment is cast — 2,213 cards in The Master of Keys's colors 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. Sigil of the Empty Throne — makes a token
4. Dawnhart Geist — gains you 2 life
5. Mesa Enchantress — draws you 1 card
6. Blightcaster — shrinks a creature by -2/-2
7. Blessed Spirits — puts a +1/+1 counter on itself
8. Celestial Ancient — puts a counter on a creature
9. Secret Arcade // Dusty Parlor — puts that spell's mana value counters on a creature
10. Presence of the Master — counters a spell

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

a nontoken enchantment enters the battlefield — 2,241 cards in The Master of Keys's colors 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 — 2,268 cards in The Master of Keys's colors can cause this (The Master of Keys is one).

When The Master of Keys enters:

1. Victor, Valgavoth's Seneschal — surveils
2. Doomwake Giant — shrinks a creature by -1/-1
3. Cacophony Unleashed — turns something into a creature
4. Ghostly Dancers — makes a token
5. Thassa's Devourer — mills a card
6. Archon of Sun's Grace — makes a token
7. Unwilling Vessel — puts a possession counter on itself
8. Gremlin Tamer — makes a token
9. Killian, Decisive Mentor — taps a creature
10. Thoughtrender Lamia — makes an opponent discard a card

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

a card in a graveyard — 4,724 cards in The Master of Keys's colors can cause this (The Master of Keys is one).

1. Gale, Waterdeep Prodigy — The Master of Keys puts cards into the graveyard that Gale, Waterdeep Prodigy can bring back
2. Transplant Theorist — The Master of Keys puts cards into the graveyard that Transplant Theorist can bring back
3. Heart-Shaped Herb — The Master of Keys puts cards into the graveyard that Heart-Shaped Herb can bring back
4. Wayward Angel — The Master of Keys fills your graveyard toward the 7 or more cards Wayward Angel needs
5. Rescue from the Underworld — The Master of Keys puts cards into the graveyard that Rescue from the Underworld can bring back
6. Victimize — The Master of Keys puts cards into the graveyard that Victimize can bring back
7. Enlightened Confidant — The Master of Keys puts cards into the graveyard that Enlightened Confidant can bring back
8. Tergrid, God of Fright // Tergrid's Lantern — The Master of Keys puts cards into the graveyard that Tergrid, God of Fright // Tergrid's Lantern can bring back
9. Sivriss, Nightmare Speaker — The Master of Keys puts cards into the graveyard that Sivriss, Nightmare Speaker 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

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

anything goes to a graveyard — 4,724 cards in The Master of Keys's colors 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

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

anything attacks — 9,697 cards in The Master of Keys's colors 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. Temmet, Naktamun's Will — draws you 1 card
4. Grim Javelineer — gives +1/+0
5. ED-E, Lonesome Eyebot — puts a quest counter on itself
6. Surgical Suite // Hospital Room — puts a counter on a creature
7. Fire Navy Trebuchet — makes a token
8. Obsessive Pursuit — makes you lose life
9. Guide of Souls — triggers
10. Gossip's Talent — triggers

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

a creature attacks — 9,697 cards in The Master of Keys's colors can cause this (The Master of Keys is one).

When The Master of Keys attacks:

1. Adaptive Omnitool — searches a library
2. Kindred Discovery — draws you 1 card
3. Invasion of New Capenna // Holy Frazzle-Cannon — puts counters on a permanent
4. Chorale of the Void — brings a card back
5. Saw — sacrifices a creature

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

a creature enters the battlefield — 10,850 cards in The Master of Keys's colors can cause this (The Master of Keys is one).

When The Master of Keys enters:

1. Pollywog Prodigy — puts a counter on itself
2. Airbender Ascension — puts a quest counter on itself
3. Ray Fillet, Wave Warrior — puts a counter on itself
4. Aetherstorm Roc — puts a counter on a permanent you control

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

anything enters the battlefield — 15,308 cards in The Master of Keys's colors 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

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