Bolas's Citadel

an enchantment leaves the battlefield — 1 card in the game can cause this (Bolas's Citadel is one).

1. Dual Nature — When Dual Nature leaves the battlefield thanks to Bolas's Citadel, it exiles an enchantment
2. Tombstone Stairwell — When Tombstone Stairwell leaves the battlefield thanks to Bolas's Citadel, it kills an enchantment
3. Necromancy — When Necromancy leaves the battlefield thanks to Bolas's Citadel, it triggers
4. Sporogenesis — When Sporogenesis leaves the battlefield thanks to Bolas's Citadel, it triggers
5. Diabolic Servitude — When Diabolic Servitude leaves the battlefield thanks to Bolas's Citadel, it exiles a creature or enchantment

anything leaves the battlefield — 1 card in the game can cause this (Bolas's Citadel is one).

1. Chainer, Dementia Master — When Chainer, Dementia Master leaves the battlefield thanks to Bolas's Citadel, it exiles a Nightmare

a land is played — 97 cards in the game can cause this (Bolas's Citadel is one).

When a land plays a land thanks to Bolas's Citadel:

1. Flubs, the Fool — draws you 1 card
2. Infernal Sovereign — draws you 1 card
3. Shadow of the Goblin — deals 1 damage
4. The Endstone — draws you 1 card
5. Horn of Greed — makes a player draw 1 card
6. Pangosaur — triggers
7. City of Traitors — sacrifices itself

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

a battle in a graveyard — 129 cards in the game can cause this (Bolas's Citadel is one).

Bolas's Citadel puts cards into the:

1. The Emperor of Palamecia // The Lord Master of Hell — graveyard, and The Emperor of Palamecia // The Lord Master of Hell gets bigger
2. Builder's Talent — graveyard that Builder's Talent can bring back
3. Tasigur, the Golden Fang — graveyard that Tasigur, the Golden Fang can bring back
4. Serpent of the Pass — graveyard, and Serpent of the Pass gets bigger
5. Emeria Shepherd — graveyard that Emeria Shepherd can bring back
6. Moment of Reckoning — graveyard that Moment of Reckoning can bring back
7. Serra Paragon — graveyard that Serra Paragon can bring back
8. Muldrotha, the Gravetide — graveyard that Muldrotha, the Gravetide can bring back
9. Deadbridge Chant — graveyard that Deadbridge Chant can bring back
10. Loamcrafter Faun — graveyard that Loamcrafter Faun can bring back

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

a battle is put into a graveyard from the battlefield — 129 cards in the game can cause this (Bolas's Citadel is one).

1. Martyr's Bond — When Bolas's Citadel is put into a graveyard from the battlefield, Martyr's Bond makes an opponent sacrifice a permanent

a spell is cast — 155 cards in the game can cause this (Bolas's Citadel is one).

1. Shanid, Sleepers' Scourge — When Bolas's Citadel is cast, Shanid, Sleepers' Scourge draws you 1 card
2. Glaring Fleshraker — When a spell is cast thanks to Bolas's Citadel, Glaring Fleshraker makes a token
3. The Kingpin of Crime — When a spell is cast thanks to Bolas's Citadel, The Kingpin of Crime drains each opponent
4. Leader's Talent — When a spell is cast thanks to Bolas's Citadel, Leader's Talent puts a counter on a creature
5. Elena, Turk Recruit — When Bolas's Citadel is cast, Elena, Turk Recruit puts a +1/+1 counter on itself
6. Demigod of Revenge — When Demigod of Revenge is cast thanks to Bolas's Citadel, it brings a card back
7. Sauron, Lord of the Rings — When Sauron, Lord of the Rings is cast thanks to Bolas's Citadel, it puts 5 counters on an Orc or Army
8. Nita, Forum Conciliator — When a spell is cast thanks to Bolas's Citadel, Nita, Forum Conciliator puts a counter on a creature
9. Treasury Thrull — When a spell is cast thanks to Bolas's Citadel, Treasury Thrull drains each opponent
10. Norin the Wary — When a spell is cast thanks to Bolas's Citadel, Norin the Wary flickers itself

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

a planeswalker in a graveyard — 232 cards in the game can cause this (Bolas's Citadel is one).

Bolas's Citadel puts cards into the:

1. Liliana the Repentant — graveyard that Liliana the Repentant can bring back
2. Invasion of Tolvada // The Broken Sky — graveyard that Invasion of Tolvada // The Broken Sky can bring back
3. Winter, Tormented Loner — graveyard, and Winter, Tormented Loner gets bigger
4. Pestilent Cauldron // Restorative Burst — graveyard that Pestilent Cauldron // Restorative Burst can bring back
5. The Eldest Reborn — graveyard that The Eldest Reborn can bring back
6. Blood on the Snow — graveyard that Blood on the Snow can bring back
7. Yawgmoth's Vile Offering — graveyard that Yawgmoth's Vile Offering can bring back
8. Dark Intimations — graveyard that Dark Intimations can bring back
9. Overlord of the Balemurk — graveyard that Overlord of the Balemurk can bring back
10. Nicol Bolas, the Ravager // Nicol Bolas, the Arisen — graveyard that Nicol Bolas, the Ravager // Nicol Bolas, the Arisen can bring back

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

a planeswalker is put into a graveyard from the battlefield — 232 cards in the game can cause this (Bolas's Citadel is one).

1. Carth the Lion — When a planeswalker dies thanks to Bolas's Citadel, Carth the Lion searches a library
2. Massacre Girl, Most Wanted — When a creature dies thanks to Bolas's Citadel, Massacre Girl, Most Wanted deals 1 damage
3. Kaya's Ghostform — When a creature dies thanks to Bolas's Citadel, Kaya's Ghostform brings a card back
4. Edgar, Ancient Bloodlord — When a creature dies thanks to Bolas's Citadel, Edgar, Ancient Bloodlord gains you 1 life
5. Cruel Celebrant — When a creature dies thanks to Bolas's Citadel, Cruel Celebrant makes each opponent lose 1 life
6. Rising Populace — When a creature dies thanks to Bolas's Citadel, Rising Populace puts a +1/+1 counter on itself
7. Ajani's Last Stand — When a creature dies thanks to Bolas's Citadel, Ajani's Last Stand sacrifices itself

1 other card cares about it too. These are the ones with the most connections.

an enchantment is sacrificed — 588 cards in the game can cause this (Bolas's Citadel is one).

1. Narci, Fable Singer — When an enchantment is sacrificed thanks to Bolas's Citadel, Narci, Fable Singer draws you 1 card

a nontoken artifact is sacrificed — 740 cards in the game can cause this (Bolas's Citadel is one).

1. Bag of Devouring — When a creature is sacrificed thanks to Bolas's Citadel, Bag of Devouring exiles it

an artifact is sacrificed — 761 cards in the game can cause this (Bolas's Citadel is one).

1. Megatron, Tyrant // Megatron, Destructive Force — When an artifact is sacrificed thanks to Bolas's Citadel, Megatron, Tyrant // Megatron, Destructive Force deals the sacrificed artifact's mana value damage
2. Carrot Cake — When Carrot Cake is sacrificed thanks to Bolas's Citadel, it makes a token

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

a creature in a graveyard — 2,769 cards in the game can cause this (Bolas's Citadel is one).

1. Tethmos High Priest — Bolas's Citadel puts cards into the graveyard that Tethmos High Priest can bring back

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

a creature dies — 2,830 cards in the game can cause this (Bolas's Citadel is one).

1. Voice of Resurgence — When Voice of Resurgence dies thanks to Bolas's Citadel, it makes a token
2. Auspicious Ancestor — When Auspicious Ancestor dies thanks to Bolas's Citadel, it gains you 3 life

470 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 (Bolas's Citadel is one).

1. Quintorius Kand — Bolas's Citadel puts cards into the graveyard that Quintorius Kand can bring back
2. Hunting Grounds — Bolas's Citadel fills your graveyard toward the 7 or more cards Hunting Grounds needs

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