First Responder

anything leaves the battlefield — 1 card in the game can cause this (First Responder is one).

1. Shaun, Father of Synths — When Shaun, Father of Synths leaves the battlefield thanks to First Responder, it exiles a Synth you control

a nontoken creature leaves the battlefield — 4,133 cards in the game can cause this (First Responder is one).

When a creature leaves the battlefield thanks to First Responder:

1. Tokka & Rahzar, Unsupervised — puts a +1/+1 counter on itself
2. Splinter, the Mentor — makes a token
3. Rat King, Pale Piper — makes a token
4. Dual Nature — exiles a creature

a creature leaves the battlefield — 4,238 cards in the game can cause this (First Responder is one).

1. Lunarch Veteran // Luminous Phantom — When a creature leaves the battlefield thanks to First Responder, Lunarch Veteran // Luminous Phantom gains you 1 life
2. Rapacious Guest — When Rapacious Guest leaves the battlefield thanks to First Responder, it makes each opponent lose life equal to its power
3. Extractor Demon — When a creature leaves the battlefield thanks to First Responder, Extractor Demon mills a card
4. Aang, Airbending Master — When a creature leaves the battlefield thanks to First Responder, Aang, Airbending Master puts a counter on a permanent
5. Dour Port-Mage — When a creature leaves the battlefield thanks to First Responder, Dour Port-Mage draws you 1 card
6. Vela the Night-Clad — When a creature leaves the battlefield thanks to First Responder, Vela the Night-Clad makes each opponent lose 1 life
7. Champions of the Perfect — When Champions of the Perfect leaves the battlefield thanks to First Responder, it triggers
8. Phantasmal Mount — When Phantasmal Mount leaves the battlefield thanks to First Responder, it triggers
9. Funeral March — When a creature leaves the battlefield thanks to First Responder, Funeral March makes a player sacrifice a creature
10. Sally Sparrow — When a creature leaves the battlefield thanks to First Responder, Sally Sparrow triggers

21 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 (First Responder is one).

1. All Will Be One — When a permanent gets a counter thanks to First Responder, All Will Be One deals that much damage
2. Lonis, Genetics Expert — When Lonis, Genetics Expert gets a counter thanks to First Responder, it triggers

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 (First Responder is one).

When First Responder attacks:

1. Far Fortune, End Boss — deals 1 damage
2. Temmet, Naktamun's Will — draws you 1 card
3. Grim Javelineer — gives +1/+0
4. Invisible Woman — triggers
5. Caesar, Legion's Emperor — sacrifices a creature
6. Guide of Souls — triggers
7. Campsite Cuisine — sacrifices a Food
8. Gossip's Talent — triggers
9. Banon, the Returners' Leader — draws and discards
10. Toph, Earthbending Master — puts a counter on a permanent

112 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 (First Responder is one).

When First Responder attacks:

1. Adaptive Omnitool — searches a library
2. Anthem of Rakdos — gives +2/+0
3. Kindred Discovery — draws you 1 card
4. Invasion of New Capenna // Holy Frazzle-Cannon — puts counters on a permanent
5. Chorale of the Void — brings a card back
6. Saw — sacrifices a creature
7. Gisa's Favorite Shovel — makes an opponent sacrifice a creature
8. Ultima Weapon — kills a creature an opponent controls
9. Path of Mettle // Metzali, Tower of Triumph — triggers
10. Total War — kills a creature

180 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 (First Responder is one).

When First Responder blocks:

1. Mage Hunters' Onslaught — makes a player lose 1 life
2. Carnage Gladiator — makes a player lose 1 life
3. Barrow-Blade — strips abilities
4. Heat of Battle — deals 1 damage
5. Battle Strain — deals 1 damage
6. Favor of the Woods — gains you 3 life
7. Tide of War — sacrifices a creature
8. Dead-Iron Sledge — kills a creature
9. Dwindle — kills a creature
10. Shield of the Righteous — triggers

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

a nontoken creature attacks — 17,934 cards in the game can cause this (First Responder is one).

When First Responder attacks:

1. Mardu Ascendancy — makes a token
2. Basri Ket — makes a token
3. Militia's Pride — makes a token

a creature deals combat damage — 17,934 cards in the game can cause this (First Responder is one).

When First Responder deals combat damage:

1. Locutus of Borg — makes a token
2. Antagonist Incorporator — makes a token
3. Hive Mind Coprocessor — makes you lose life

194 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 (First Responder is one).

When First Responder 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

299 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 (First Responder is one).

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

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