Short version at the bottom.

I killed the "Watch King" went back to get the NPC with the gun, and he followed me back to where i fought the "Watch King" spoke to the Gun NPC and he said that he will wait there.
Went away (used the teleport) to change the "Blessing/Curse" to Goundham WIll (or something like that) went back he was gone and the Fight against the "Watch King" started anew but without the actual enemy because he was dead and didn't respawned but the healthbar went slowly down but never reached 0 so if I hadnt the blessing from the blue woman i would have been stuck there (but i could jump on a pillar up and escape from the room) the battle music and the Boss Healthbar never dissapeared even using the teleport thing (didnt tried dieing tho) also the game wont save any progress that i made after entering the battle which shouldnt have been triggered in the first place because he was already dead

1) Kill "Watch King"
2) get the NPC with the gun to follow you where you Killed the "Watch King"
3) Leave him there and Teleport to get another Blessing.
4) return to the place where the "Watch King" was, which triggers the Boss fight but without respawning the "Watch King" and get trapped in a Battle which will never end because theres no enemy to fight against also getting stuck and if you manage to leave the game wont save any progress after your "Prison Break" ;)

Thanks alot.