if an Unsevering skill is something that can only be applied by someone else, rather than the person who was Severed, that'd work to prevent a constant back-and-forth because presumably if you were Severed for being a dick you'd have a harder time of convincing someone to help you.

Although admittedly all of this is academic at this point - I don't even know if an unsevering skill would even be possible in the first place. The mods would have to be the judge of that (and of whether it's even necessary in the first place. They might decide that a counter skill isn't the way to go, or that the Severances are just fine the way they are)