In the first room, jump up to ascend the platforms while attacking or avoiding by two Peeping Eyes. The next room has an infinite spawn of Ghouls and a single Black Panther. The third room is similar to the first room, but it contains a Draculina and Peeping Eye. Draculinas fly above with a bat and will attack by kicking down or sending the bat to attack. At the top left is a red chest containing a HP Max up. Go right into the next room that contains two Black Panthers and then go up to a room with another Draculina. The next room has a Tin Man that will quickly attack from the right. Attack or jump over it and go up to the large room. To the right is a save room and to the left is a warp room. The top left has a red chest that contains a MP Max up. The top right leads to a boss.
Wallman attacks by throwing three bombs that explode in straight lines horizontally and vertically. He then uses the Paries glyph to go through the wall behind and bring back more bombs or a Super Potion to drink. This pattern is repeated. If you attack him while he is about to drink the super potion, he will drop it and you can pick it up. This can only be done once. He cannot be killed through attacks. The trick to defeating him is to absorb his Paries glyph. If you defeat him without taking damage, a blue chest will appear that contains a Wallman Medal.
After you defeat Wallman, equip the Paries glyph and go through the wall. Break the statue and get the Melio Confodere glyph. The next room has another Tin Man and Draculina. Continue on and watch out for the Black Panther when you jump down. Ignore the Blood Skeleton and drop down. The next room has a Black Panther and Peeping Eye. Go right and drop down.
At this point the path splits. The right path leads to a warp room at the end and the entrance to the Forsaken Cloister. You can't get very far into the Forsaken Cloister, but it may be worthwhile to absorb the Nitesco glyph from a Nova Skeleton. The left path leads through a dining and kitchen area. To the far left is a breakable wall that leads to a hidden room. It contains a statue with the Refectio glyph and a red chest that contains the Hanged Man Ring. Go back to the previous room and drop down while avoiding the three Mad Butchers. They will run towards you and try to slash you with their chainsaws. Continue down and stay on the platform. There are two Tin Men below. Go down past two more Draculinas. The next room has three more Mad Butchers. The bottom right leads to more Tin Men and then another room of Mad Butchers. At the top right of room with the Mad Butchers is a breakable box that has a hidden Cream Puff. The last room has a Dextros Custos glyph.
You will have to backtrack to the room in the Castle Entrance where you needed the Paries glyph to continue.