Dream Halls + Conspiracy Theorist + Petals of Insight + Voidwielder

Dream Halls

Conspiracy Theorist

Petals of Insight

Voidwielder

How it works

1. Cast Petals of Insight by discarding Voidwielder.
2. Conspiracy Theorist triggers, exiling Voidwielder 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 Voidwielder from exile by discarding Petals of Insight.
5. Conspiracy Theorist triggers, exiling Petals of Insight and allowing you to cast it from exile this turn.
6. Voidwielder enters the battlefield, returning itself from the battlefield to your hand.
7. Cast Petals of Insight from exile by discarding Voidwielder.
8. Repeat from step 2.

This brilliant loop is built around Dream Halls, which bypasses normal mana costs entirely by letting you discard a card that shares a color with the spell you are casting. By alternating between casting Petals of Insight and Voidwielder, you continually feed each card as discard fodder to pay for the other. Conspiracy Theorist is the crucial enabler here, using its triggered ability whenever you discard nonland cards to exile them and immediately allow you to cast them from exile. Meanwhile, Voidwielder's enters-the-battlefield ability self-bounces, neatly resetting itself so the cycle can feed endlessly into infinite storm count, magecraft triggers, and entry-and-leave-the-battlefield effects.