Main strategy: get Lightning to do combat damage somehow, then cast a shitton of instants and sorceries to do direct damage. As a backup, direct damage spells give prowess triggers, then double that with stagger afterwards.

Add Lightning, Army of One once FIN is added to deckbox. Suplex would also be good removal... it's just strictly better Abrade. Throw in some Self-Destruct for using Screaming Nemesis and Stagger together.

Consider using Haste Magic together with Self-Destruct for the Screaming Nemesis / Stagger combo. That's four cards, but they're all cards that have other uses as well. Haste Magic + Lightning AoO can help ensure she deals damage and triggers stagger, Haste Magic + Self-Destruct is useful for any creature, so I think there's enough synergy there that a four-card combo isn't asking too much.

Sideboard has graveyard removal, artifact removal, and enchantment removal to target various decks. celestial armor is intended for getting lightning over the fence against decks with lots of blockers, or to give some response to flyer-heavy decks.