I started again a bit in college, where I learned enough to play properly with other peoples decks
While it's possible it could support brand new builds of Restore Balance or Living End that drop the cascade spells (and along with them the "no cards with CMC 2 or less" restriction), it may be more likely that Yahenni's Expertise finds a home in the existing build of Restore Balance (and maybe even Living End) as a way to cast the namesake cards when you happen to draw them naturally
Its also just kind of Lier, Disciple of the Drowned with more colors, and some storm potential with a deck full of spells
With three mana, you can play plenty of great commanders, cast tons of mana rocks, and have access to all sorts of other ramp spells
9 Fiery Temper Burning Madness Fiery Temper is a card that, outside of desperation, you'll never actually pay its normal casting cost
Uncapping the mana available to players at the start of the game makes it more reasonable to allow potent attacks on mana, like Wasteland, Daze and Armageddon, adding a whole new strategic element to the game