edhseer Commander synergy, explained
Instant
Mana cost: {U}{R}
Look at the top four cards of your library. You may reveal an instant or sorcery card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.
on-cast — searches a library
Flashback {3}{U}{R}
Causes: nothing.
Cares about: nothing.
an instant is cast — 3,931 cards in the game can cause this (Arcane Infusion is one).
When Arcane Infusion 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 (Arcane Infusion is one).
When Arcane Infusion is cast:
5 other cards care about it too. These are the ones with the most connections.