Horizon of Progress: Strong multi-color fixing that can tag out for a new card and has a Terrain Generator ability
Those who played back when it was legal know how often the game would revolve around a Prophet of Kruphix Recurring Nightmare The play pattern of repeatedly looping the same creatures, and without an interaction window because the returning of the enchantment is a cost, and the combo potential, leads to a card that is more likely to create harm and frustration than good
Plus, hes a Werewolf on the backside, and although most payoffs are in red and green, thats still a popular creature type
The mana generated by Sage of the Unknowable's activated ability can be used to activate any ability, not just abilities of colorless sources
But, while I can still jam a turn one Llanowar Elves and be happy, thats what Ill be doing