My favorite is Devastating Mastery as a four-mana Planar Cleansing that sweeps all dorks, planeswalkers, artifacts, and enchantments
That helps the accessibility, but I think the game came out, to some extent, a little more difficult than we wanted it to be
If you manage to get Flotsom, Ursula's Spy out as well, you'll have a strong Evasive combo that will be hard for your opponent to deal with
The adventure portion, Alter Fate, doesn't bring a creature back directly to the battlefield, but the hand is good enough for two mana - Especially when you consider that you have access to a 2/2 with flying after you've cast it
That ability is "When you move your venture marker into this room, [effect]." After you move your venture marker into the last room of a dungeon and that room's ability resolves (or otherwise leaves the stack), the dungeon leaves the game and you have now completed it