If you're not familiar with the combo, the short version is that Archfiend of the Dross enters the battlefield with four oil counters, we have to remove one on our upkeep, and we lose the game when we run out of oil counters
The deck starts by playing a number of creature cards with strong enchantment/saga synergy including cards that can reset your sagas (Brago, Ferropede), generate creature tokens when you cast enchantments (archon), enchantment reanimate (Ghen), saga copy (Weaver of Harmony), card draw (Sythis, Mesa Enchantress, Satyr Enchanter), fetch (Zur, Moon-Blessed Cleric), and more
The retro art style and being one of only 500 cards also makes it much more valuable
The main theme of the deck is using the "madness" discard mechanic to cycle through your deck in search of your more powerful cards
If you choose to pay the impending cost rather than the mana cost, you're still casting the spell