That is, one that produces all 5 colors of mana
Bastion of Remembrance Battle of Hoover Dam Cauldron of Essence Crowded Crypt Dark Prophecy Death's Presence Dictate of Erebos Elemental Time Flamingo Embalmed Ascendant Fallen Angel Avatar Foster Funeral Room // Awakening Hall Funeral Room // Awakening Hall Furious Forebear Ghost Lantern Ghost Lantern Grave Pact Grave Venerations Jar of Eyeballs Liliana, Dreadhorde General Lolth, Spider Queen Meathook Massacre II Moldervine Reclamation Norn's Wellspring Phyrexian Vivisector Promise of Tomorrow Proper Burial Relic Vial Reyhan, Last of the Abzan Rofellos Sothera, the Supervoid The Cauldron of Eternity The Meathook Massacre Vigil for the Lost Waltz of Rage Warhost's Frenzy Weatherlight Compleated
What would be even better for us would be finding a way to do it more than once
Until then, have fun, and may the force be with brew.
Rot-Curse Raksasha, for example, is a massive body that already has a significant downside
Unfortunately, theres still one seller whos either very lazy or extremely hopeful that someone will stumble across his $5 (plus .99 shipping!) copy