Arena Rector

a planeswalker enters the battlefield — 366 cards in the game can cause this (Arena Rector is one).

1. Liliana the Repentant — When Arena Rector enters, Liliana the Repentant mills a card
2. Liliana the Faultless — When Arena Rector enters, Liliana the Faultless gains you 1 life
3. Builder's Talent — When a planeswalker enters thanks to Arena Rector, Builder's Talent puts a counter on a creature
4. Brainstealer Dragon — When a planeswalker enters thanks to Arena Rector, Brainstealer Dragon makes a player lose life equal to its mana value
5. Cloudstone Curio — When a planeswalker enters thanks to Arena Rector, Cloudstone Curio triggers

a Cleric enters the battlefield — 722 cards in the game can cause this (Arena Rector is one).

1. Cleric of Life's Bond — When Arena Rector enters, Cleric of Life's Bond gains you 1 life

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

a nontoken creature is exiled — 995 cards in the game can cause this (Arena Rector is one).

1. The War Games — When Arena Rector is exiled, The War Games exiles a Warrior

a creature is exiled — 1,003 cards in the game can cause this (Arena Rector is one).

When Arena Rector is exiled:

1. Ashnod's Intervention — brings a card back
2. Syr Vondam, Sunstar Exemplar — puts a +1/+1 counter on itself
3. Kaya, Spirits' Justice — copies a permanent
4. Soulherder — puts a +1/+1 counter on itself
5. Kaya's Ghostform — blinks a permanent

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

a creature leaves a graveyard — 1,302 cards in the game can cause this (Arena Rector is one).

When Arena Rector leaves a graveyard:

1. Grim Reaper's Scythe — makes a token
2. Syr Konrad, the Grim — deals 1 damage
3. Cyan, Vengeful Samurai — puts a +1/+1 counter on itself
4. Along the Crooked Way — puts a counter on a Goblin or Army
5. Skeleton Crew — makes a token
6. Desecrated Tomb — makes a token
7. Chalk Outline — makes a token
8. Insidious Roots — makes a token
9. Undead Hand Ninja — makes each opponent lose 1 life
10. Erebos's Titan — triggers

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

anything is exiled — 2,497 cards in the game can cause this (Arena Rector is one).

1. The War Doctor — When Arena Rector is exiled, The War Doctor puts a time counter on itself
2. God-Eternal Oketra — When God-Eternal Oketra is exiled thanks to Arena Rector, it triggers

anything leaves a graveyard — 2,503 cards in the game can cause this (Arena Rector is one).

When Arena Rector leaves a graveyard:

1. Blastoneuron — makes each opponent lose 1 life
2. Defiled Crypt // Cadaver Lab — makes a token
3. Teval, the Balanced Scale — makes a token
4. Hologram Stalker — makes a token
5. Tormod, the Desecrator — makes a token
6. Quintorius, Field Historian — makes a token
7. Garrison Excavator — makes a token
8. Amzu, Swarm's Hunger — makes a token
9. Kirol, History Buff // Pack a Punch — becomes prepared
10. Teval's Judgment — triggers

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

a Human enters the battlefield — 4,639 cards in the game can cause this (Arena Rector is one).

When Arena Rector enters:

1. General Kudro of Drannith — hits a graveyard
2. Heronblade Elite — puts a +1/+1 counter on itself
3. Kyler, Sigardian Emissary — puts a +1/+1 counter on itself
4. Thalia's Lieutenant — puts a +1/+1 counter on itself
5. Champion of the Parish — puts a +1/+1 counter on itself
6. Captain of the Mists — untaps itself
7. Erkenbrand, Lord of Westfold — gives +1/+0
8. Beregond of the Guard — gives +1/+1
9. Théoden, King of Rohan — grants double strike
10. Lossarnach Captain — taps a creature an opponent controls

2 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 (Arena Rector is one).

When Arena Rector attacks:

1. Far Fortune, End Boss — deals 1 damage
2. Temmet, Naktamun's Will — draws you 1 card
3. Invisible Woman — triggers
4. Caesar, Legion's Emperor — sacrifices a creature
5. Guide of Souls — triggers
6. Campsite Cuisine — sacrifices a Food

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

a creature attacks — 17,934 cards in the game can cause this (Arena Rector is one).

When Arena Rector attacks:

1. Adaptive Omnitool — searches a library
2. Saw — sacrifices a creature

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

a creature blocks — 17,934 cards in the game can cause this (Arena Rector is one).

1. Tide of War — When Arena Rector blocks, Tide of War sacrifices a creature

27 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 (Arena Rector is one).

When Arena Rector enters:

1. Slash, Reptile Rampager — deals 2 damage
2. Ray Fillet, Wave Warrior — puts a counter on itself
3. The Neutrinos — gets +1/+0
4. Wingnut, Bat on the Belfry — grants flying, haste and menace
5. Aetherstorm Roc — puts a counter on a permanent you control
6. Raphael, Most Attitude — exiles a card from your library

314 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 (Arena Rector is one).

1. Prowl, Stoic Strategist // Prowl, Pursuit Vehicle — When Arena Rector enters, Prowl, Stoic Strategist // Prowl, Pursuit Vehicle puts a +1/+1 counter on itself

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