Mortuary

Whenever a creature is put into your graveyard from the battlefield, put that card on top of your library.

Gyruda, Doom of Depths

Companion — Your starting deck contains only cards with even mana values. (If this card is your chosen companion, you may put it into your hand from outside the game for {3} as a sorcery.)
When Gyruda enters, each player mills four cards. Put a creature card with an even mana value from among the milled cards onto the battlefield under your control.

Arcane Signet

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

Command Tower

Sol Ring

Exotic Orchard

{T}: Add one mana of any color that a land an opponent controls could produce.