Twilight Orb
From TPPC Wiki
What it does: Unlocks Unown Tower Phase #1. Also evolves 
Doublade into 
Aegislash (Shield).
Where to get it: Attach 6 Rare Metals to your lineup and beat the Evolution Gym with a Fire Pokémon.
How to unlock phase: Just have your starting Pokémon with the item attached and go to the Unown Tower.
