User blog comment:EmpyreanSmoke/Supernatural Q&A/@comment-95.112.133.60-20150912215637/@comment-24834479-20150912234146

Im not sure whether or not the things that can kill an angel while in a vessel can kill them while in their light form. I would say that things such as Leviathan and angel blades can kill them in their fallen smoke form, but im not so sure about their light form.