Mavinda, Students' Advocate [Strixhaven: School of Mages] Magnets create a 4/4 gold Dragon

create a 4/4 gold Dragon creature token with flying and roll a d20 (a twenty-sided die)

instead look at the top X cards of your library

Most human scholars believe that Merfolk are the survivors of sunken Atlantis

if Runaway Steam-Kin has fewer than three +1/+1 counters on it

Mavinda, Students' Advocate [Strixhaven: School of Mages] Magnets create a 4/4 gold DragonSet: Strixhaven: School of Mages Type: Legendary Creature Bird Advisor Rarity: Mythic Cost: {2}{W} Flying {0}: You may cast target instant or sorcery card from your graveyard this turn. If that spell doesn't target a creature you control, it costs {8} more to cast this way. If that spell would be put into your graveyard, exile it instead. Activate only once each turn. (You still pay the spell's costs. Timing rules for the spell still apply.)