Her activated ability (tap to copy a spell you control, usable only after you've cast three or more spells that turn) is the conversion piece: once you've cast enough cheap spells to unlock the tap ability, you can copy an instant or sorcery to untap her and repeat. Sol Ring and Mind Stone provide early mana acceleration, while Arcane Signet and Talisman of Creativity fix your colors. Your cantrips—Brainstorm and Consider, plus 4 more card-draw pieces—are load-bearing: they cost one mana, trigger Stella's exile ability, and let you dig for combo pieces or selection. Cerulean Wisps is the linchpin: it costs one mana, untaps Stella when you cast it, and draws a card, creating the infinite loop once you've cast three spells. For the Dualcaster Mage combo, you cast Molten Duplication targeting a creature you control, then cast Dualcaster Mage in response; Dualcaster's enter trigger copies Molten Duplication, creating a token copy of Dualcaster, and the loop repeats infinitely. The Storm-Kiln Artist line requires Underworld Breach already in play: you cast Brain Freeze from your graveyard using escape (paying its mana cost plus exiling three other cards), and each prior spell that turn creates a copy of Brain Freeze via storm; Storm-Kiln Artist triggers on each cast or copy, creating Treasures that fund the next escape activation. Merchant Scroll, Solve the Equation, and Muddle the Mixture tutor for your instant and sorcery pieces, while Thassa's Oracle serves as your payoff—when she enters, she checks your devotion to blue (the total blue mana symbols in your permanents' costs) and wins if that number exceeds your library size, which the combo loops easily achieve. March of Swirling Mist and Traumatic Critique are infinite-mana outlets: once you have unlimited mana or spell copies, you can cast them repeatedly to phase out blockers or drain the table.
Stella Lee, Wild Card is a compact combo engine that wins through three distinct verified loops. The Stella Lee, Wild Card + Cerulean Wisps loop produces Infinite copies of one instant or sorcery, Infinite magecraft triggers on its own — it needs a separate finisher to actually win. A secondary combo pairs Dualcaster Mage with Molten Duplication to create infinite token copies and sacrifice triggers. The tertiary route chains Storm-Kiln Artist, Underworld Breach, and Brain Freeze: Underworld Breach lets you escape spells from your graveyard, Brain Freeze's storm mechanic copies itself for each prior spell that turn, and Storm-Kiln Artist creates Treasure tokens on each cast or copy, funding the loop until opponents are milled out. All three lines leverage your low mana curve and cheap cantrips to assemble pieces by turn 3–5, then convert spell velocity into a lethal burst.