Honestly I like the combat mechanics, but it gets too easy too fast and there´s little to no punishment for having a servant loose to an adventurer. I have some ideas to improve upon it. Knowing this message will be TLDR. I will split it in diferent sub parts to make it easier to read

1. Permadeath. If your servants fight an oponent too strong for them and they lose, let them die. If you dont have the correct facilities to resurrect them, then you lose them forever.

2. Give the Adventurers that raid your Dungeon Jobs that will affect how they behave in your Dungeon.

-Looter: Will go for your gold mines and will abandon the Dungeon if he manages to get out of one of your mines (After fighting or just passing though) If they leave the dungeon, you loose 10% of your gold. (Easy to defeat)

-Saboteur: Will destroy parts of your dungeon, forcing you to dig them again and build from scratch. They will leave after destroying 3 facilities of any kind. (Easy)

-Slaver: will try to kidnap your servants by defeating them. He will try to get the weakest of them all, activelly avoiding the strongest ones if possible. Will leave after defeating 1 of your servants and will make it impossible for you to revive him (Medium)

-Hypnotist: Will make your servants bertay you by using powerful lust spells. Forcing you to fight thoug your own to get to him. This one want to take everything from you so he wont leave (Medium)

-Hero: This one is a boss level adventurer, will take the shortest route to get to you and defeat you. (Hard)