Karn's Bastion

you proliferate — 90 cards in the game can cause this (Karn's Bastion is one).

When Karn's Bastion proliferates:

1. Scheming Aspirant — makes each opponent lose 2 life
2. Ezuri, Stalker of Spheres — draws you 1 card
3. Voidwing Hybrid — returns itself from the graveyard
4. Venser, Corpse Puppet — triggers

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

a land enters the battlefield — 1,560 cards in the game can cause this (Karn's Bastion is one).

When Karn's Bastion enters:

1. Primeval Bounty — gains you 3 life
2. Toph, Earthbending Master — puts a counter on a permanent
3. Dancing from Dark to Dawn — makes a token
4. Emeria Shepherd — brings a card back
5. Quest for the Necropolis — puts a quest counter on itself
6. Soul Stair Expedition — puts a quest counter on itself
7. Nissa of Shadowed Boughs — puts counters on a permanent
8. Thranduil, Sindarin Liege // Silvan Rally — makes a token
9. Silvan Reveler — returns itself from the graveyard
10. Floral Evoker — puts a +1/+1 counter on itself

199 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 (Karn's Bastion is one).

When a permanent gets a counter thanks to Karn's Bastion:

1. Aether Revolt — deals that much damage
2. Territorial Gorger — gets +2/+2
3. Fabrication Module — puts a counter on a creature
4. All Will Be One — deals that much damage

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