I just finished my one-man playthrough with a warrior. I made a couple mistakes with my build, and I also bugged out a couple quests, which was especially important on the last fight since they apparently would've given me two support people if I hadn't said I'd be back later, so I really had to do the last fight solo. I still won that fight, though, which leads me to my point:
Fleeing is overpowered.
The way I did the last fight was, I'd sneak in, kill one guy, and then flee. I did this for everyone in the final fight except for Bishop Alexander and the void worm. This way I managed to fight both Bishop Alexander and the void worm one-on-one (the void worm didn't come out until Alex was dead for some reason). I'm pretty sure I could not have done that fight another way. There was another fight in the swamp that I did a similar way, near the statue you get Bless at (hardest fight to solo outside of the final fight).
There doesn't seem to be any sort of penalty or risk factor involved in fleeing. So, as I did in those two fights, you can just use it over and over again until you kill everyone. As such, what would've been an impossible fight becomes relatively easy (Bishop Alexander was easy without support units, as I could just keep him stunlocked until he died; the void worm actually ended up being a harder fight due to this tactic, as it normally would fight your enemies as well as you).
I don't know what the right solution would be, here, honestly. Maybe implement a chance to fail to flee. Maybe have a minimum distance between your character and the nearest enemy, so as to restrict your ability to flee (Bishop Alexander was close enough to hit me with an attack of opportunity one of the times I fled). Give it an AP cost. Something.
