Activate Mite Overseer by paying 3W/P, creating two creature tokens.
When the creature tokens enter the battlefield, Ajani's Welcome triggers twice, causing you to gain 2 life.
Activate Ashnod's Altar twice by sacrificing the creature tokens, adding CCCC.
Repeat.
This clever loop begins with Mite Overseer, whose activated ability brings Phyrexian Mite tokens into the fray, a creation process supercharged by Stridehangar Automaton to simultaneously flood the board with extra Thopter tokens. As these creatures enter, Ajani's Welcome effortlessly turns each arrival into a steady stream of life gain to offset any costs. Finally, Ashnod's Altar converts those freshly minted tokens back into a surplus of colorless mana, giving you all the fuel needed to reactivate Mite Overseer and keep the engine running infinitely.