mtg kozilek commander deck Kozilek, Butcher of Truth | Rise of the Eldrazi Foil | Modern Hao Han Magic Kozilek, Compleated - Mystery Booster

If youre trying to do something engine-y like Jeskai Ascendancy, your opponent is going to have answers due to Force of Vigor

You'll also find antagonists including Hugo Kupka and events including the Clash of the Eikons

Because these cards arent at an especially high power level I expect the regular Magic Online offerings to eschew the mechanic entirely, and if you do want to incorporate dungeons into one of your Cubes I recommend going heavy on the mechanic so that players have good odds of actually completing one

Excluding everyone who joins Ramza's party, by the end of The Stinger, you can count the remaining still living major characters on one hand

In fact, its pretty easy (I wonder if I ever say differently about a card): If you are about to pay for a spell less than 3 mana, you get to pay 3 mana