The two abilities encourage you to cast all your instants and sorceries on your opponent's turn
While it may eventually become too popular for its own good and suffer against heavy countermeasures, getting that much recognition in one of the highest-powered Standard formats in Magic history is an achievement for draft chaff everywhere
This includes Aura spells, triggered abilities, and anything else that targets a permanent with ward
A bunch of extra Rampant Growths and artifact tokens on top of a creature that improves your taplands all adds up to a powerful package
Like most Magic: The Gathering cards, the value of Elminster depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (Commander Legends: Battle for Baldur's Gate)
Avoid Fate One of the very few mono-green counterspells is Avoid Fate, and Im constantly surprised I dont see more people running this green instant in EDH