Maester Seymour

a Human gets a counter — 326 cards in the game can cause this (Maester Seymour is one).

1. Cloaked Cadet — When a creature gets a counter thanks to Maester Seymour, Cloaked Cadet draws you 1 card

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

1. Cleric of Life's Bond — When Maester Seymour 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.

an Elf attacks — 723 cards in the game can cause this (Maester Seymour is one).

When Maester Seymour attacks:

1. Celeborn the Wise — scries
2. Tyvar the Bellicose — grants deathtouch
3. Harald Unites the Elves — shrinks a creature by -1/-1
4. Arboreal Alliance — triggers

a nontoken Elf enters the battlefield — 728 cards in the game can cause this (Maester Seymour is one).

1. Wirewood Hivemaster — When Maester Seymour enters, Wirewood Hivemaster makes a token

an Elf enters the battlefield — 752 cards in the game can cause this (Maester Seymour is one).

When Maester Seymour enters:

1. Wolverine Riders — gains you its toughness life
2. Elvish Warmaster — makes a token
3. Thranduil, the Elvenking — draws you 2 cards
4. Elvish Vanguard — puts a +1/+1 counter on itself
5. Marwyn, the Nurturer — puts a +1/+1 counter on itself
6. Woodland Weavemaster — gets +1/+1
7. High Perfect Morcant — puts a counter on a permanent an opponent controls
8. Maralen, Fae Ascendant — exiles a card from an opponent's library

a creature gets a counter — 2,691 cards in the game can cause this (Maester Seymour is one).

1. Scurry Oak — When Scurry Oak gets a counter thanks to Maester Seymour, it makes a token
2. Fathom Mage — When Fathom Mage gets a counter thanks to Maester Seymour, it draws you 1 card
3. Hollowmurk Siege — When a creature gets a counter thanks to Maester Seymour, Hollowmurk Siege draws you 1 card
4. Ant-Man, Colony Commander — When a creature gets a counter thanks to Maester Seymour, Ant-Man, Colony Commander makes a token
5. Earth Kingdom General — When a creature gets a counter thanks to Maester Seymour, Earth Kingdom General gains you that much life
6. Casey Jones, Back Alley Brute — When a creature gets a counter thanks to Maester Seymour, Casey Jones, Back Alley Brute deals that much damage
7. Generous Patron — When Maester Seymour gets a counter, Generous Patron draws you 1 card
8. Shalai and Hallar — When a creature gets a counter thanks to Maester Seymour, Shalai and Hallar deals that much damage
9. Danny Pink — When a creature gets a counter thanks to Maester Seymour, Danny Pink draws you 1 card
10. Enduring Scalelord — When a creature gets a counter thanks to Maester Seymour, Enduring Scalelord puts a +1/+1 counter on itself

33 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 (Maester Seymour is one).

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

7 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 (Maester Seymour is one).

When Maester Seymour 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 (Maester Seymour is one).

When Maester Seymour 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

119 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 (Maester Seymour is one).

When Maester Seymour attacks:

1. Adaptive Omnitool — searches a library
2. Anthem of Rakdos — gives +2/+0
3. Kindred Discovery — draws you 1 card
4. Saw — sacrifices a creature

189 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 (Maester Seymour is one).

1. Tide of War — When Maester Seymour 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 (Maester Seymour is one).

When Maester Seymour enters:

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

313 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 (Maester Seymour is one).

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

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