I mean, we all know that Lucifer is invulnerable to fire, and in s4 when Chloe asked him how did he get through that giant firey explosion, he said that was one of the perks of living in hell for so long. So my question is: is lucifer invulnerable to fire only because he lived in hell, or also because he was an angel? In that case, wouldnt the other angels be invulnerable to it too?