I completed the entire campaign with this hero and nothing happened. The battle with Kujin is actually easy; if she also had a ballista (I was leveling up fire magic), it would be even easier. In this battle, the "Wrath of the Horde" spell definitely ruled; almost all the devils fell from it, and the hounds also suffered.

I still managed to stop the orcs. Apparently, for this, you need to click on the Kujin icon at least 20 times. Now it was really easy to deal with Grol. He couldn't do anything against the cyclops!

Added 7 minutes later
Vitos st, you're rushing. First, you need to go through the portal guarded by a demon, to the upper left part of the map, take the elven castle, then Ilay will take the fourth demon castle, and then through the portal from Zehir's dungeon, you can go directly to Claw, where reinforcements will be waiting for him.