For Biorr to help you fight these bosses, you must first find him and free him from his prison cell in Boletarian Palace. The walkthrough below tells you how.
Where is Biorr in Demon’s Souls?
Biorr can be found near the Tower Knight Archstone in Boletarian Palace. There is a locked wooden door near the Tower Knight Fog Gate (the entrance to the Tower Knight boss fight) barring the way to a dungeon and Biorr’s cell.
For another reference point, the door is located between the Tower Knight Archstone and the gate leading to The Lord’s Path (the gate guarded by the Blue Eye Knight and the three archers leading outside the castle walls).
How to Open the Door Leading to the Dungeon and Biorr’s Cell
To open the door, you need the Iron Key Ring, which is dropped by a Fat Official in The Inner Ward. The Inner Ward is the area locked by a large Fog Gate just beyond the Tower Knight Archstone.
To dissolve the Fog Gate, you must first defeat an Arch Demon. The easiest Arch Demon to defeat is the Dragon God, which is found in Stonefang Tunnel following the Flamelurker boss fight.
Once you have defeated Dragon God, or one of the other Arch Demons such as Old Monk (Tower of Latria), Maiden Astraea (Valley of Defilement), or Storm King (Shrine of Storms), return to the Tower Knight Archstone and the Fog Gate will dissolve automatically, giving you access to The Inner Ward.
A cutscene will play and the doors will open.
How to Get the Iron Key Ring
Go through the doors and into the courtyard beyond with two carriages full of barking dogs. Defeat the two dogs near the fountain, and go up the large set of stairs leading up to a Fat Official.
When you reach the Fat Official, another cutscene will play. After the cutscene, turn right, toward a stack of crates and barrels. Three Boletarian Soldiers will burst through the crates and barrels, revealing a small passageway. Defeat the Soldiers and follow the path ahead. Defeat the Soldier and Spearman in the next area.
To proceed, you can go left and down the stairs, or you can roll off the edge of the landing just to the right of the stairs. Either way, you will have to fight an Imperial Spy, so be careful of its (very) strong attacks that can deplete both your stamina and health.
After defeating the Spy, follow the path around and up to a large landing with lunch/picnic tables. Kill the Archer on the landing; be mindful that a Spy will sometimes come down the stairs behind you and attack.
From this landing, go up the stairs and stop just past the first torch on the left wall. This will trigger the Soldier at the top of the stairs to release the flaming boulder in front of him. Run back to dodge the boulder and fight the Spy coming down the stairs after you.
Now go back up the stairs, minding the Archer in the first hallway to the right, the Soldier coming down the stairs, and the Spy in the second hallway to the right. At the top of the stairs, you’ll see a Fat Official and three Archers in front of you.
Follow the stairs that go up to the left. Kill the Red Eye Knight in the corridor, and continue along the path. You will emerge into a large open area with lunch/picnic tables on the left and the three Archers ahead of you, just to the right (the same three Archers you saw before fighting the Red Eye Knight).
A Spy will drop down just to your left. Kill them and stay left, along the very edge of the area. Go up the wooden ladder in front of you, then another wooden ladder.
At the top, you’ll be faced with two Spearmen and two Soldiers. Try to take them out quickly; the Fat Official will be walking up the steps toward you.
A Spy will also appear if you get too close to the main stairs leading higher up, so try to stay near the wooden ladder you just came up until you thin the enemies out.
Now, all you have to do is kill the Fat Official and take the Iron Keychain. With the Keychain in hand, go back to the door at the Tower Knight Archstone and open it (do this before you fight Penetrator in The Inner Ward). Follow the path down and eventually, you’ll turn left into an area full of cells and a Fat Official.
Go straight ahead, and Biorr’s cell is the last cell on the right, just past a torch on the right wall and a large cart on the left. It’s hard to see him because he’s sitting in complete darkness, but just unlock the cell and walk inside.
How to Get Biorr to Help You Fight Penetrator
After you’ve freed Biorr, all you have to do for him to help you with Penetrator is enter the Penetrator boss fight, and he will spawn on the right side of the area, near the Fog Gate. It does not matter if you’re in Soul form or Human form.
Unfortunately, Biorr doesn’t do much damage to Penetrator, but he will distract the boss for you, allowing you, or other players you’ve summoned, to focus on damage instead of defense.
How to Get Biorr to Help You Fight the Blue Dragon
If Biorr survives the fight with Penetrator, he will “help” you fight the Blue Dragon in 1-4, The King’s Tower. I say “help” because Biorr doesn’t really do much in this fight and can be easily killed by the Blue Dragon’s fire.
Note: If you are trying to complete the Mephistopheles questline, you should kill Biorr before either fight to eliminate the risk of him dying and negating the entire questline.
And that’s all you need to know about how to find and rescue Biorr, of the Twin Fangs in Demon’s Souls, as well as how to get his help during two of the games harder boss/more laborious boss fights. If you found this guide helpful, consider giving it a share!
