It's easier to perform this combo with creatures in play / graveyards that allow additional mana, like Mikeaus or Woodfall Primus
If that wasnt monumental enough for you, you can still plan ahead by phasing things out that you dont want to lose
shaving a mana from it with The Ur-Dragons eminence makes it quite powerful when it comes to casting discounted Dragons from the top of your library
A classic enchantment commander is none other than Zur the EnchanterZur the Enchanter, which would probably love to turn a problem creature into a Humble Merchant during combat
A free Raise Dead every upkeeparguably a better one since it recurs sagas and artifactsis a fine investment considering that you always draw at least one card
Legendary Enchantment Enchantment (CTRL to add secondary) Planeswalker Elminster Whenever you scry, the next instant or sorcery spell you cast this turn costs less to cast, where X is the number of cards looked at while scrying this way