door cards mtg Guardian of the Great (foil) put a charge counter on this artifact Unlocking a door - MTG

Overlord of Balemurk pairs nicely with Walk-In Closet Cellar

Overlord Cycle Each 'biome' of Duskmourn has an Overlord, an Avatar Horror with Impending, which enters as an enchantment, and doesn't become a creature until its last time counter is removed

As for the plane itself, theres a little to work with in Orzhov both for enchantment and lifegain synergies, although neither are naturally prominent in this precon

Only limitation is the colors, but it will function well for you if you can cast it

Black Lotus, The Moxen, and Ragavan are prime examples, as they provide an overwhelming resource or tempo advantage from the very first turn