Ivy, Gleeful Spellthief, Cloudstone Curio, and Treachery

Prerequisites

• Ivy, Gleeful Spellthief on the battlefield
• Cloudstone Curio on the battlefield
• Treachery in hand
• available

Steps

1. Cast Treachery by paying , targeting another creature
2. Ivy triggers, copying Treachery, with the copy targeting Ivy
3. Resolve the copy of Treachery, attaching it to Ivy
4. When the Treachery copy enters, it and Cloudstone Curio triggers
5. Resolve the Treachery trigger, untapping up to five lands
6. Resolve the Cloudstone Curio trigger, returning nothing to your hand
7. Resolve the original Treachery, attaching it to the targeted creature and causing you to gain control of that creature
8. When Treachery enters, it and Cloudstone Curio triggers
9. Holding priority, activate up to five lands by tapping them, adding an amount of mana
10. Resolve the Treachery trigger, untapping up to five lands
11. Resolve the Cloudstone Curio trigger, returning the other Aura from the battlefield to your hand if it's on the battlefield
12. If it isn't on the battlefield, then return nothing to your hand
13. Activate up to five lands by tapping them, adding an amount of mana
14. Cast the other Aura by paying its mana cost, targeting another creature
15. Ivy triggers, copying the Aura, with the copy targeting Ivy
16. Resolve the copy of the Aura, attaching it to Ivy
17. When the Aura copy enters, Cloudstone Curio triggers
18. Choose to return nothing to your hand
19. Resolve the original Aura, attaching it to the targeted creature
20. When the Aura enters, Cloudstone Curio triggers, returning the nontoken Treachery from the battlefield to your hand
21. Repeat

Results

• Gain control of all creatures
• Infinite copies of a specific enchantment
• Infinite mana lands you control can produce
• Infinite storm count
• Infinite untap of lands you control