Threefold Signal

you scry — 420 cards in the game can cause this (Threefold Signal is one).

When Threefold Signal scries:

1. Prudent Fateseer // Peer Review — gives +1/+0
2. Diviner of Victory // Unwind History — gets +1/+1
3. Saheeli, Consul of Oversight — makes a token
4. Celeborn the Wise — makes your creatures bigger
5. Proft, Consulting Detective — puts a +1/+1 counter on itself
6. Matoya, Archon Elder — draws you 1 card
7. Denzilore Fatehold — puts a counter on a creature
8. Elminster — costs less
9. Elrond, Master of Healing — puts a counter on a creature
10. Galadriel of Lothlórien — puts a land onto the battlefield

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

an artifact is cast — 3,683 cards in the game can cause this (Threefold Signal is one).

When Threefold Signal is cast:

1. Mendicant Core, Guidelight — copies a spell
2. Sai, Master Thopterist — makes a token
3. Ravenous Robots — makes a token
4. Pinnacle Emissary — makes a token
5. Mirrodin Besieged — makes a token
6. Poetic Ingenuity — makes a token
7. Digsite Engineer — makes a token
8. Myrsmith — makes a token
9. Riddlesmith — draws you 1 card
10. Dr. Madison Li — puts a counter on a permanent you control

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

a nontoken artifact enters the battlefield — 3,768 cards in the game can cause this (Threefold Signal is one).

When Threefold Signal enters:

1. Ultron, Artificial Malevolence — makes a token
2. The Prydwen, Steel Flagship — makes a token
3. Conquest Mission — puts a quest counter on itself
4. Surge Conductor — proliferates
5. Replication Specialist — makes a token
6. Weapons Manufacturing — makes a token
7. Mirrorworks — makes a token

an artifact enters the battlefield — 4,643 cards in the game can cause this (Threefold Signal is one).

When Threefold Signal enters:

1. Transplant Theorist — draws you 1 card
2. Elvish Archivist — puts 2 +1/+1 counters on itself
3. Golbez, Crystal Collector — surveils
4. Sludge Strider — makes a player lose 1 life
5. Underhanded Designs — makes each opponent lose 1 life
6. Mechan Assembler — makes a token
7. Glassdust Hulk — gets +1/+1
8. Rook Turret — draws you 1 card
9. Hedron Detonator — deals 1 damage
10. Pactdoll Terror — makes each opponent lose 1 life

55 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 (Threefold Signal is one).

When Threefold Signal enters:

1. HYDRA Assault Robot — deals 1 damage
2. Era of Innovation — puts a counter on a permanent you control

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

anything is cast — 31,128 cards in the game can cause this (Threefold Signal is one).

When Threefold Signal is cast:

1. Sokka, Bold Boomeranger — puts a +1/+1 counter on itself
2. Saheeli, Radiant Creator — puts a counter on a permanent you control

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