mtg card buylist How to Magic Cards | Selling Your Magic Cards for Cash or Store Credit with Kingdom you may reveal the top card of your library TrollTraderCards

Every other timing rule for casting spells still applies: If the mayhem card is an instant, you can cast it any time you have priority that turn, but if it's a creature you can only cast it at sorcery speed (unless another effect gives it flash)

Wilhelt, the Rotcleaver Wilhelt, the Rotcleaver peaked as the 11th most popular commander ever , though it's now slipped between #20-30

A similarly good option are singles from Amazon like Bloodstained Mire

1 Wall of Tanglecord

Two single-player starter decks are available for the Disney Lorcana TCG set Azurite Sea

Obviously, this isnt worth much if your creature is small, but on something like Okaun, Eye of Chaos or Primeval Spawn, youre going to be cooking with a large payoff and little downside