The Hero's Path

Decided to replay as a Warlock and found a bug. The cave where Astral is located should be darkened, but I managed to light it up almost completely using scouting and the Silent Stalker skill from a neighboring area. I haven't reached the Sphinx yet. I also lit up some kind of mess of creatures and heroes in the upper right corner of the map (in the Dungeon). I see a two-way portal there – how do I get to it?
P.S. I got an error message when sending this post. After the forum update, there were 4 of them =).