Prison Hell Quest
From Realera Wiki
Name: Prison Hell Quest.
Location: Fermur.
Requirements: Completed Fermur Hell Quest.
Reward: Silver Trophy and 15 Pair of Hellflayer Horns, 2 Crystallized Anger.
Once you complete the Fermur Hell Quest, enter the teleport next to A Ghostly Gatekeeper
The path marked with colored lines in the order first white -> yellow -> blue -> purple.
This order is due to the fact that we have to move the three levers marked in green, which block the walls, one by one.