edhseer Commander synergy, explained
Legendary Creature — Beholder
Mana cost: {4}{U}{B}
At the beginning of your upkeep, choose target opponent. Until end of turn, that player can't cast spells, you may look at the top card of their library any time, you may play the top card of their library, and you may spend mana as though it were mana of any color to cast spells this way.
triggered — taxes the table
Causes: nothing.
Cares about: an upkeep.
hits creature — 881 cards in Xanathar's colors can cause this (Xanathar is one).
5 other cards care about it too. These are the ones with the most connections.
a creature attacks — 6,258 cards in Xanathar's colors can cause this (Xanathar is one).
When Xanathar, Guild Kingpin attacks:
63 other cards care about it too. These are the ones with the most connections.
anything attacks — 6,258 cards in Xanathar's colors can cause this (Xanathar is one).
When Xanathar, Guild Kingpin attacks:
15 other cards care about it too. These are the ones with the most connections.
a creature blocks — 6,258 cards in Xanathar's colors can cause this (Xanathar is one).
When Xanathar, Guild Kingpin blocks:
4 other cards care about it too. These are the ones with the most connections.
a creature deals combat damage — 6,258 cards in Xanathar's colors can cause this (Xanathar is one).
98 other cards care about it too. These are the ones with the most connections.
a creature is cast — 6,287 cards in Xanathar's colors can cause this (Xanathar is one).
When Xanathar, Guild Kingpin is cast:
19 other cards care about it too. These are the ones with the most connections.
a nontoken creature enters the battlefield — 6,508 cards in Xanathar's colors can cause this (Xanathar is one).
When Xanathar, Guild Kingpin enters:
3 other cards care about it too. These are the ones with the most connections.
a creature enters the battlefield — 6,953 cards in Xanathar's colors can cause this (Xanathar is one).
When Xanathar, Guild Kingpin enters:
60 other cards care about it too. These are the ones with the most connections.