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 the battlefield, 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.

Sidisi, Brood Tyrant

Whenever Sidisi, Brood Tyrant enters the battlefield or attacks, mill three cards.
Whenever one or more creature cards are put into your graveyard from your library, create a 2/2 black Zombie creature token.