You can use this benevolently, to prevent yourself or another player from being wiped out, or maliciously, as part of a dastardly combo deck that puts the card under an Isochron Scepter and casts it every single turn cycle to stay in the game
A well-built deck with a smooth mana curve and a good mix of creatures and spells will function just fine, even if it doesn't have much synergy
Based around scrying and casting high value instants and sorceries, Elminster's static ability reduces the mana cost of the next instant or sorcery you would cast by the number of cards you looked at the last time you scried
(And prone to not casting any spells for a while.) What you want to do instead is first, figure out the core that's going to enable your more expensive cards to work here
Saheeli helped destroy the Immortal Sun, a powerful device that prevented planeswalkers from escaping, while Huatli fought to protect civilians from Bolass minions