We talked about this for a very long time
Six mana can be a lot, but red has no shortage of rituals or Treasure tokens to get this out early, and while you cant cascade from copies of spells, you can discover if you cast cards like Trumpeting Carnosaur or Hit the Mother Lode, which then gives you more copies
Discard & Cast From Exile First up, let's talk card advantage: Inti effectly "replaces" any discarded card with one we can play from exile
We decided we liked the back being a copy effect, although one you could only use once because it's uncommon
To show how efficient this card is for the right deck, the final versions of Miracle Grow, which were dubbed Super Grow, used Mystic Enforcer as a finisher, since by the time you'd get around to casting it you had an all but guaranteed 6/6 flyer for four mana
You'll likely have to shave a few Instants and Sorceries, but that's the price you pay for smiting your enemies