Gruul Signet

Sol Ring

Mind Stone

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

Izzet Signet

Arcane Signet

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

Simic Signet

Skyclave Relic

Kicker {3}
Indestructible
When Skyclave Relic enters, if it was kicked, create two tapped tokens that are copies of Skyclave Relic.
{T}: Add one mana of any color.

Rashmi and Ragavan

Whenever you cast your first spell during each of your turns, exile the top card of target opponent's library and create a Treasure token. Then you may cast the exiled card without paying its mana cost if it's a spell with mana value less than the number of artifacts you control. If you don't cast it this way, you may cast it this turn.