Dream Halls, Containment Construct, Petals of Insight, and Man-o'-War

Prerequisites

• Dream Halls on the battlefield
• Containment Construct on the battlefield
• Petals of Insight in hand
• Man-o'-War in hand

Steps

1. Cast Petals of Insight by discarding Man-o'-War
2. Containment Construct triggers, exiling Man-o'-War and allowing you to cast it from exile this turn
3. Resolve Petals of Insight, putting the top three cards of your library on the bottom of your library, and returning Petals of Insight to your hand
4. Cast Man-o'-War from exile by discarding Petals of Insight
5. Containment Construct triggers, exiling Petals of Insight and allowing you to cast it from exile this turn
6. Man-o'-War enters the battlefield, returning itself from the battlefield to your hand
7. Cast Petals of Insight from exile by discarding Man-o'-War
8. Repeat from step 2

Results

• Infinite ETB
• Infinite LTB
• Infinite magecraft triggers
• Infinite self-discard triggers
• Infinite storm count