Ruby Storm is a pure combo deck that wins by chaining rituals through Ruby Medallion and Ral, Monsoon Mage to generate storm count, so your entire game plan is disrupting that chain before it goes off. Mystical Dispute is your best counter here — it hits Ral and Past in Flames for just one mana, and Tishana's Tidebinder can shut off Ral's triggered ability entirely if he resolves. Endurance comes in as a fast threat that also exiles their graveyard, cutting off Past in Flames recursion and forcing them to win in a single pass. Leyline Binding is slow and does nothing to stop a combo turn, and Scion of Draco provides no disruption against a spell-based combo deck, so those come out. Force of Negation is your most important card in the deck here — protect it at all costs and prioritize countering Ral or a lethal storm turn.