The Forsaken Cloister has two entrances that connect to the Library on the left and the Mechanical Tower on the right. From either side, go to the center where there is a Cerberus statue. If you approach from the Mechanical Tower, there is a wall that is blocking the path. Stand on the switch next to it to open the wall. At the Cerberus statue, you will need to equip the Dextro Custos, Sinestro Custos, and Arma Custos glyphs and use them to light each head of the statue. The statue will lower and open the vertical path. Continue upwards while avoiding all of the flying enemies. The top left platform can be broken to reveal a hidden Eisbein. At the top, there is a save room to left and the Final Approach to the right.