Dream Halls, Sandstorm Eidolon, and Sparkcaster

Prerequisites

• Dream Halls on the battlefield
• Sandstorm Eidolon in hand
• Sparkcaster in hand

Steps

1. Cast Sparkcaster by discarding Sandstorm Eidolon
2. Sandstorm Eidolon triggers from your graveyard, returning from your graveyard to your hand
3. Sparkcaster enters the battlefield, triggering twice
4. Resolve the first Sparkcaster trigger, dealing 1 damage to target player or planeswalker
5. Resolve the second Sparkcaster trigger, returning Sparkcaster from the battlefield to your hand
6. Repeat

Results

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