$emych, did he overtake you in the Dungeon? Then you need to replay it and plan your route better.

I remember, I managed to get the Boots of Swiftness on my first turn there. I think they were guarded by monks or inquisitors. Then I found another pair of boots somewhere - for the Dungeon. After descending underground, I changed my boots. And I also improved my Logistics skill. Moreover, in the next mission, you need to run quickly to compete with the enemy. Besides, Logistics suits a demon very well.