Sol Ring

Boros Signet

Gruul Signet

Scroll of Fate

{T}: Manifest a card from your hand. (Put that card onto the battlefield face down as a 2/2 creature. Turn it face up any time for its mana cost if it's a creature card.)

Selesnya Signet

Arcane Signet

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

Kaust, Eyes of the Glade

Whenever a creature you control that was turned face up this turn deals combat damage to a player, draw a card.
{T}: Turn target face-down attacking creature you control face up.