Arcane Signet

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

Call for Aid

Gain control of all creatures target opponent controls until end of turn. Untap those creatures. They gain haste until end of turn. You can't attack that player this turn. You can't sacrifice those creatures this turn.

Insurrection

Untap all creatures and gain control of them until end of turn. They gain haste until end of turn.

Plains

Twist Allegiance

You and target opponent each gain control of all creatures the other controls until end of turn. Untap those creatures. Those creatures gain haste until end of turn.

Wayfarer's Bauble

{2}, {T}, Sacrifice Wayfarer's Bauble: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Avarice Totem

{5}: Exchange control of Avarice Totem and target nonland permanent.

Guardian Idol

Guardian Idol enters tapped.
{T}: Add {C}.
{2}: Guardian Idol becomes a 2/2 Golem artifact creature until end of turn.

Coldsteel Heart

Coldsteel Heart enters tapped.
As Coldsteel Heart enters, choose a color.
{T}: Add one mana of the chosen color.

Mass Mutiny

For each opponent, gain control of up to one target creature that player controls until end of turn. Untap those creatures. They gain haste until end of turn.

Custody Battle

Enchant creature
Enchanted creature has "At the beginning of your upkeep, target opponent gains control of this creature unless you sacrifice a land."

Aurelia, the Law Above

Flying, vigilance, haste
Whenever a player attacks with three or more creatures, you draw a card.
Whenever a player attacks with five or more creatures, Aurelia, the Law Above deals 3 damage to each of your opponents and you gain 3 life.

Mountain

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Mirage Mirror

{2}: Mirage Mirror becomes a copy of target artifact, creature, enchantment, or land until end of turn.