Sigil was a very dangerous place.
Yet such an important place was extremely special, which was that the Lady of Pain, who governed Sigil, was extremely unfriendly toward deities.
This unfriendliness targeted all deities without any differential treatment, whether evil gods or good gods, whether coming from Mount Celestia or Baator; in the eyes of the Lady of Pain, all deities were treated the same.
That was completely ignoring them!
Sigil was an absolute domain controlled by the Lady of Pain; although her power was not considered the greatest within the Multiverse, inside Sigil she was forever the strongest.
Regarding the Lady of Pain of Sigil, a text was recorded as follows: "The Lady of Pain is a symbol of power (people usually call her the Lady). She has no dwelling, no temple, no palace, and she also has no worshippers (adherents). Those foolish people who pray to her had better prepare to regret it, because the Lady of Pain will mercilessly kill anyone who worships and believes in her!"
Sometimes, people could see her drifting down the street, her robes barely brushing the ground. However, her visiting Sigil at times did not mean that one could walk up and converse with her. She never conversed, and those fools who dared to step forward were usually harmed by her gaze. The residents of Sigil viewed her with an attitude of awe, because she was the protector of Sigil.
The Lady of Pain possessed the right to open and close various portals within Sigil. In this neutral place of Sigil, portals leading to other worlds were everywhere, and what people had to do was find them. When everyone travelled in various planes, they would in some sense arrive at Sigil. However, certain other powers were not allowed to enter the cage