edhseer Commander synergy, explained
Instant
Mana cost: {1}{G}
This spell costs {1} less to cast if it targets a Spider.
on-cast — costs 1 less
Target creature gets +4/+4 until end of turn.
on-cast — gives +4/+4
Causes: nothing.
Cares about: nothing.
an instant is cast — 3,931 cards in the game can cause this (Grow Extra Arms is one).
When Grow Extra Arms 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 (Grow Extra Arms is one).
When Grow Extra Arms is cast:
5 other cards care about it too. These are the ones with the most connections.