Cast Notorious Throng for its prowl cost by paying 5, causing you to take an extra turn after this one.
Move to your next turn.
Cast Chthonian Nightmare by paying 1.
When Chthonian Nightmare enters the battlefield, it triggers, causing you to get EEE.
Activate Chthonian Nightmare by paying EEEE, sacrificing a creature with mana value 2 or less, and returning Chthonian Nightmare from the battlefield to your hand, returning Izzet Chronarch from your graveyard to the battlefield.
When Izzet Chronarch enters the battlefield, it triggers, returning Notorious Throng from your graveyard to your hand.
Cast Chthonian Nightmare by paying 1.
When Chthonian Nightmare enters the battlefield, it triggers, causing you to get EEE.
Activate Chthonian Nightmare by paying at most EE, sacrificing Izzet Chronarch, and returning Chthonian Nightmare from the battlefield to your hand, returning a creature with mana value 2 or less from your graveyard to the battlefield.
Repeat.
This clever recursion loop unlocks an endless string of extra turns by cycling the clever Izzet Chronarch in and out of the graveyard to continually fish back Notorious Throng. The engine is fueled entirely by Chthonian Nightmare, whose clever design both generates the energy needed to reanimate your creatures and bounces itself back to your hand as a cost, letting you replay it repeatedly to trigger fresh energy supplies. Meanwhile, the initial combat damage from a Rogue allows you to cast Notorious Throng for its prowl cost in the first place, setting the stage to loop the Chronarch endlessly and secure absolute victory across formats like Commander and Legacy.