Being what he is, it is not like he will die from a simple sickness, of course... You see? He too is like this, so it cannot be natural.
[Normally Sebastian wouldn't talk about "what Lucifer is", because... demon bro code, but his head is only screwed on so straight right now. Saying Lucifer will survive is also kind of contraproductive to his earlier attempt to make Chloe direct her attention away from himself, but well. See earlier point.]
I truly do not see why he came to me for sympathy. [Nevermind he mostly wanted food...]