Sol Ring

Rising Waters

Lands don't untap during their controllers' untap steps.
At the beginning of each player's upkeep, that player untaps a land they control.

Island

Aether Barrier

Whenever a player casts a creature spell, that player sacrifices a permanent of their choice unless they pay {1}.

Mana Vault

Mana Vault doesn't untap during your untap step.
At the beginning of your upkeep, you may pay {4}. If you do, untap Mana Vault.
At the beginning of your draw step, if Mana Vault is tapped, it deals 1 damage to you.
{T}: Add {C}{C}{C}.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Llawan, Cephalid Empress

When Llawan, Cephalid Empress enters, return all blue creatures your opponents control to their owners' hands.
Your opponents can't cast blue creature spells.

Tolaria

{T}: Add {U}.
{T}: Target creature loses banding and all "bands with other" abilities until end of turn. Activate only during any upkeep step.