Boros Energy wants to deploy multiple cheap creatures and planeswalkers per turn (Ragavan, Ocelot Pride, Guide of Souls, Ajani), so High Noon's one-spell-per-turn restriction is devastating against their curve-out plan. A second Wrath of the Skies helps sweep their token-and-counter synergy board before it snowballs. Kaheera can be hard-cast as a Legendary Creature to block and stabilize against their aggressive creatures while gaining incidental value. Silence is far too narrow against a deck with many permanents already in play rather than a single key spell to counter, and Day's Undoing/Consult the Star Charts are too slow against their fast clock. Keep Solitude, Supreme Verdict, and Wrath of the Skies as your primary sweepers against their wide boards.