User blog comment:KillRoy231/What Dean should have done about the Mark/@comment-26982641-20160920050644/@comment-1031724-20160929221256

Even if they got into Hell, how would they be a threat there? Except to Crowley, of course, but then, Leviathans are also hard to kill, so cut off their heads, dip them in sodium borax, and bury the head and body separately. They'll be alive, like Chet and Edgar, just powerless to do anything. The Mark would only impact the Leviathans if they had the First Blade, or if the Leviathan-killing weapon was attempted to be used on them.