Vivi Ornitier combo

Vivi Ornitier turns every noncreature spell you cast into a +1/+1 counter and 1 damage to each opponent. The plan is to generate raw mana from rituals (Pyretic Ritual, Rite of Flame, Desperate Ritual, Lion's Eye Diamond, Lotus Petal, Simian Spirit Guide, Sol Ring, Basalt Monolith) and cheap cantrips (Opt, Ponder, Consider, Brainstorm, Gitaxian Probe) to fill the graveyard, then cast Underworld Breach: every nonland card in your graveyard gains escape (mana cost plus exile three other cards from graveyard). You recast rituals via escape to net more mana than they cost, paying the exile cost with already-used cantrips, and each recast triggers Vivi for damage and growth. Past in Flames offers a second recursion pattern via flashback on instants/sorceries. Veyran, Voice of Duality doubles magecraft/Vivi triggers when in play; Harmonic Prodigy does the same for triggered abilities of Wizards/Shamans. Storm-Kiln Artist and Guttersnipe convert every cast into Treasures or direct damage. Niv-Mizzet, Parun draws a card off each instant/sorcery cast by anyone and deals damage whenever you draw; Archmage Emeritus draws on every magecraft trigger. The main win condition is a storm-copied Grapeshot or Brain Freeze after an Underworld Breach loop, or simply enough direct damage from Vivi/Guttersnipe/Niv-Mizzet Parun to close the game outright. Underworld Breach sacrifices itself at end step, so the loop must close the same turn it's cast. Weaknesses: the deck is fragile to hand disruption and graveyard hate (grave hate shuts off Underworld Breach and Past in Flames); it depends on finding enough cheap rituals/cantrips to trigger the loop, so unlucky hands or aggressive mulligans can strand it without gas; Vivi itself is vulnerable to removal since it's the only scalable repeatable mana source. Counterspell and Flusterstorm protect the key turn.