In Dark Souls, which character is imprisoned in a cell in Sen’s Fortress?

Big Hat Logan is imprisoned in a cell in Sen’s Fortress in Dark Souls.

Logan is a powerful sorcerer from Vinheim who becomes trapped inside the fortress. The player can rescue him by finding the appropriate key and opening his cell. Once freed, he relocates to Firelink Shrine and later to the Duke’s Archives, where his storyline develops further.

His rescue gives the player access to advanced sorcery training and additional dialogue about magic, dragons, and knowledge. Logan’s oversized hat is the source of his famous nickname, while his formal identity is Big Hat Logan.

Griggs of Vinheim is another sorcerer associated with the game, but he is rescued from a locked room in the Lower Undead Burg rather than Sen’s Fortress. Laurentius is a pyromancy trainer and has a separate rescue event in the Depths.