User blog comment:General MGD 109/Who's the strongest demon/@comment-4628856-20130721224336

While Azazel was immune to most of the demonic weaknesses, there is no guarantee he was able to hold his own against Archangels: They could kill him as easily as Cas could kill any low-level demon. Also, Sam was immune to demonic powers from Lilith and another demon: it stands to reason he could have been able to use his powers on Azazel. Lilith is the very first demon, so she would most likely be more powerful than Azazel, but it could only be by a small margin: Like the difference between Michael and Lucifer is only a small margin. If Lilith and Azazel fought, Lilith could overcome him after a long fight...Maybe. Also, there is a small possibility that Cas, as a Seraph, could have killed him.