Prototype Portal + Clock of Omens + Grinding Station + Ancient Den

Prototype Portal

Clock of Omens

Grinding Station

Ancient Den

How it works

1. Activate Prototype Portal by paying 0 and tapping it, creating a token copy of Ancient Den.
2. The Ancient Den token enters, triggering Grinding Station, untapping Grinding Station.
3. Activate Clock of Omens by tapping the Ancient Den token and Grinding Station, untapping Prototype Portal.
4. Repeat.