Necropolis – “Misfortune never comes alone” [Campaign 2 – Mission 1]

Then, another question.
I can't capture the second Castle. It's always either deadly or a high threat... My hero's level is 1 higher than the Inquisitor's.
What should I do?
I've tried a quick rush.

You've been playing for a long time, try replaying.
Or, try attacking, but first, build an altar in the Castle where you can resurrect killed units.

In general, besides Salvatore, Inquisitors on this map don't stay in castles and don't mind chasing after the player; encountering them on the walls of a Fortress or Castle is a pleasant experience.