Cloudstone Curio + Hornet Queen + Mana Echoes + Chromatic Orrery

Cloudstone Curio

Hornet Queen

Mana Echoes

Chromatic Orrery

How it works

1. Activate Chromatic Orrery's first ability by tapping it, adding 5.
2. Cast Hornet Queen by paying 7.
3. Hornet Queen enters the battlefield, triggering itself, Cloudstone Curio, and Mana Echoes.
4. Resolve the Cloudstone Curio trigger, returning nothing to your hand from the battlefield.
5. Resolve the Hornet Queen trigger, creating four 1/1 Insect creature tokens with flying and deathtouch.
6. The Insects enter the battlefield, triggering Mana Echoes four times and Cloudstone Curio four times.
7. Resolve the first Cloudstone Curio trigger, returning Hornet Queen from the battlefield to your hand.
8. Resolve all remaining Cloudstone Curio triggers, returning nothing to your hand from the battlefield.
9. Resolve all Mana Echoes triggers, adding 5 for each Insect you control.
10. Repeat from step 2.