edhseer Commander synergy, explained
Land — Island
({T}: Add {U}.)
As this land enters, you may behold a Jace. If you don't, this land enters tapped.
static —
Empower Jace 2.
activated {2}{U}, {T} — puts 2 counters on it
Causes: behold.
Cares about: nothing.
an Island enters the battlefield — 64 cards in the game can cause this (Theorist's Sanctum is one).
a land enters the battlefield — 1,560 cards in the game can cause this (Theorist's Sanctum is one).
When Theorist's Sanctum enters:
199 other cards care about it too. These are the ones with the most connections.
anything enters the battlefield — 26,499 cards in the game can cause this (Theorist's Sanctum is one).
18 other cards care about it too. These are the ones with the most connections.