Gigan, Cyberclaw Terror - Gyruda, Doom of Depths (384) [Ikoria: Lair of Behemoths]

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} any time you could cast 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.