This clever mana loop relies on Pemmin's Aura turning Rimewind Taskmage into an untap engine that feeds on its own activations. Once you fulfill Rimewind Taskmage's snow permanent requirement, it can untap Lotus Vale, which compensates for the cost by tapping for three mana of any color. Meanwhile, the blue mana generated by Lotus Vale pays directly for Pemmin's Aura to untap Rimewind Taskmage, leaving you with an excess of mana on every single iteration.