Arcane Signet

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

Melek, Reforged Researcher

Melek's power and toughness are each equal to twice the number of instant and sorcery cards in your graveyard.
The first instant or sorcery spell you cast each turn costs {3} less to cast.

Steam Vents

({T}: Add {U} or {R}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Frantic Search

Draw two cards, then discard two cards. Untap up to three lands.