edhseer Commander synergy, explained
Artifact
Mana cost: {3}
Choose target non-Wall creature the active player has controlled continuously since the beginning of the turn. That player may pay {X}, where X is that creature's mana value. If they don't pay, the creature attacks this turn if able, and at the beginning of the next end step, destroy it if it didn't attack this turn. Activate only before attackers are declared.
activated {3}, {T} —
Causes: a creature dies.
Cares about: nothing.
a creature in a graveyard — 2,769 cards in the game can cause this (Arcum's Whistle is one).
Arcum's Whistle puts cards into the graveyard that:
799 other cards care about it too. These are the ones with the most connections.
a nontoken creature dies — 2,769 cards in the game can cause this (Arcum's Whistle is one).
When a creature dies thanks to Arcum's Whistle:
60 other cards care about it too. These are the ones with the most connections.
a creature dies — 2,830 cards in the game can cause this (Arcum's Whistle is one).
When a creature dies thanks to Arcum's Whistle:
450 other cards care about it too. These are the ones with the most connections.
a creature goes to a graveyard — 3,011 cards in the game can cause this (Arcum's Whistle is one).
When a creature hits the graveyard thanks to Arcum's Whistle:
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 (Arcum's Whistle is one).
When Arcum's Whistle is cast:
277 other cards care about it too. These are the ones with the most connections.
an artifact enters the battlefield — 4,643 cards in the game can cause this (Arcum's Whistle is one).
68 other cards care about it too. These are the ones with the most connections.
a card in a graveyard — 7,589 cards in the game can cause this (Arcum's Whistle is one).
443 other cards care about it too. These are the ones with the most connections.