Ruby Storm wants to chain cheap rituals and cantrips into Grapeshot or Past in Flames, so Spell Pierce is premium disruption that can stop their key enabler or combo turn outright while they're tapped out from rituals. Meltdown, held for the right moment, sweeps away Ral, Monsoon Mage or a resolved threat, though its main job is just being a cheap X-spell you can hold up. Removal spells like Unholy Heat are largely dead since they run almost no relevant creatures, so trim them along with Mishra's Bauble to lower your curve and maximize interaction density. Prioritize racing and disrupting their mana rather than trading resources.