I guess an "unchain all" hotkey would work perfectly. Not necessarily "unchain all/chain all".
I mean, after any fight you could use a hotkey to unchain every char in order to prevent death. After that, you can move your chars to a safe spot and chain them mannually again.
Not sure if pause button would be a good idea, it could become annoying. For example, in the burial grounds there are at least 3 consecutive fights on a very dangerous field. And you would have to pause after every fight. It'd bother me.
