edhseer Commander synergy, explained
Instant
Mana cost: {3}{G}{W}
Untap all creatures you control. They gain hexproof and indestructible until end of turn.
on-cast — untaps a permanent
on-cast — grants a keyword
Causes: untap a creature.
Cares about: nothing.
a creature untaps — 519 cards in the game can cause this (Join Shields is one).
an instant is cast — 3,931 cards in the game can cause this (Join Shields is one).
When Join Shields 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 (Join Shields is one).
When Join Shields is cast:
5 other cards care about it too. These are the ones with the most connections.