This ingenious engine spins an infinite mana and landfall loop centered around a token copy of Mistvault Bridge imprinted onto Prototype Portal for zero mana. As each new Bridge enters the battlefield, Tiller Engine steps in to immediately untap it, allowing you to tap the token for blue mana. To keep the gears turning, Filigree Sages untaps Prototype Portal so you can repeat the process, all while Agatha of the Vile Cauldron acts as a crucial cost-reducer to make the Sages' untap ability cheap enough to sustain the loop.