Instant and sorcery spells you cast have storm. (Whenever you cast an instant or sorcery spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)
Cast cheap cantrips and rituals to build up a high spell count, then unleash a payoff instant/sorcery that storms off into multiple lethal copies. You ramp into your 7-mana dragon, protect a long turn with rituals and cost reducers, and chain spells so each subsequent cast copies for every spell before it that turn.
Innate storm on every instant and sorcery is an enormous payoff with no extra deckbuilding cost
Flying evasive body can also just close games as a beater while you protect with Ward—Pay 5 life
Burn and draw spells become exponentially better as the turn goes on
Rewards a lean, low-curve spellslinger build that's resilient to creature removal
Seven mana and color-identity bound to UR means it dies to counters/removal and is slow to deploy
No card advantage engine in the command zone—you must supply your own gas
Storm rewards a single big turn, making you vulnerable to stax, taxes, and graveyard hate
Vulnerable to losing the dragon repeatedly since storm only works while it's on the battlefield
Generates mana per spell cast, fueling longer chains that storm bigger.
Lower your curve and add fast mana (Sol Ring, Mana Vault, ritual effects like Pyretic Ritual and Desperate Ritual) plus cost reducers (Goblin Electromancer, Baral) to push toward consistent turn-three-to-five storm kills. Add tutors (Mystical Tutor, Gamble) and redundant payoffs (Tendrils-style effects, Aetherflux Reservoir) so you can find and combo through interaction. Finally, lean on Underworld Breach loops and counterspell protection to make the storm turn nearly uninterruptible at higher power levels.