World of the Regret | Bitterblack Isle - Dark Arisen DLC Dragon's Dogma Guide

Riftstones that you use to summon your Pawns are damaged and you will need to repair them before you can actually use them

You will encounter mostly skeletons and zombies, and one large "boss" skeleton. However, it does not act like a normal boss, so set it on fire and hit hard (you can even knock it over or throw it up in the air).

Watch out for the monster from the chest. You will often need to heal yourself and it will try to digest you

Be careful when you open chests as you can be attacked by a specific monster that awaits you in on of the chests. It can kill you in a matter of seconds if it catches you, so once you free yourself, don't try to fight it and run away.

Gorecyclops will not cause any trouble until you attack it

Move on until you reach another pair of green doors. Take the stairs and get to the arena where an imprisoned Gorecyclops awaits. It is a more powerful, bigger and well armored version of a traditional cyclops. However, when it comes to combat techniques it is quite the same (vulnerable to ice). The major difference is that climbing it and jumping down will result in a very painful fall. Furthermore, his armor has spikes which will constantly cause damage. The only safe place on its body are its shoulders - Damage that you inflict from this place is rather low but it is a good way to draw the creature's attention away from other team members, and the monster can't throw you off (it will try to do that by moving but the loss of stamina is extremely low).

At the top of the stairs you will find Void Key that unlocks your way in Duskmoon Tower

One way or another, you don't have to fight this boss. It is chained to the wall, and will set itself free after you take half or the entire life bar. Make your way to the top and kill skeleton mages. You will find Void Key that is required to open the door in Duskmoon Tower. Head back there.