edhseer Commander synergy, explained
Instant
Mana cost: {2}{B}{B}
Choose target creature. If it's attacking, it can't be blocked this turn. If it's blocking, prevent all combat damage that would be dealt this combat by it and each creature it's blocking.
on-cast — restricts what can block it
on-cast —
Causes: prevented creature .
Cares about: nothing.
damage is prevented — 568 cards in the game can cause this (Sewers of Estark is one).
When a creature has damage prevented thanks to Sewers of Estark:
an instant is cast — 3,931 cards in the game can cause this (Sewers of Estark is one).
When Sewers of Estark is cast:
427 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 (Sewers of Estark is one).
When Sewers of Estark is cast:
5 other cards care about it too. These are the ones with the most connections.