Magnus’s RPG empire on the portal.

Since I am invisible, I slipped through the army of the dead without anyone noticing. I entered the city.

You entered the city; it would have been better if you hadn't. The stench of death is everywhere, and there's a three-moon eclipse. And here's the guild of necromancers; they have ancient scrolls. It would be best to destroy everything there and run away, and if possible, steal a few folios, like the Book of Helya, and also soul vessels so that the necromancers don't transform into liches. This will stop them for a while.