Cast Invasion of Arcavios by paying ({2} magic symbol) due to Heliod and Chromatic Orrery.
When Invasion of Arcavios enters the battlefield, it triggers, searching your library or graveyard for Paradoxical Outcome, if needed, and putting it into your hand.
Cast Paradoxical Outcome by paying ({1} magic symbol) due to Heliod and Chromatic Orrery, returning Chromatic Orrery and Invasion of Arcavios from the battlefield to your hand.
Repeat.
If opponents have drawn six or more cards this turn, this combo nets near-infinite mana.