Ugin's Labyrinth
Being able to gain infinite life and infinite colorless mana means we can just Aetherflux Reservoir everyone out of the game if we draw the necessary cards, and slowing our opponents down gives us time to draw the combo pieces we need
(Artifacts, legendaries, and Sagas are historic.) Sacrifice three Foods: Return target historic card from your graveyard to your hand
If the discard was something more universal like lands or blue cards instead of artifacts, or always just one card, while retaining its instant cost it would probably get more play than Fact or Fiction, mostly for occupying a slot on the curve in less demand
Now that might sound like a lot of money for a small cardboard rectangle, but it's about $1,000 less than similar graded versions of the card were going for in mid-February
Then it works in a few builds - the first is Dragons