They've left him alone in his cell.
He can't really be said to be lucid but he has very acute instincts for when there's someone and when he's alone - it's the last of his senses to depart him - and he's alone.
And then suddenly he isn't.
"Okay. I think it'll be good for your brothers to have you back, even in pieces, and I think you'll recover a lot. In the meantime, you two have this really unhelpful thing going on where you hate making people miserable and the reality of your situation makes the kobold miserable and you vary both in your capacity to lie about it and your interest in doing that. Have you considered living with people who won't be miserable -"
"There aren't any. I will continue making people miserable for as long as I exist and then when I stop that will make them all miserable too and I do not know how to change that except by recovering faster so I can lie better."
"You're not making me miserable. Pissed off at the Enemy, and more sympathetically inclined towards your host just by some sense you've suffered enough for the lot of them."
"Well, indulge the pretense a little, if it helps, or I can claim to be Melkor and promise this one's going to last awhile, if that helps. I don't know how much you remember but you used to trust me; you still can."
"Is the idea here to just throw everything at people, see where they stumble, so you're better calibrated on which topics to cover for..."
"If it helps I can stick around until sunrise, then people might begin to wonder why I'm talking to a Feanorian instead of doing something productive."
And eventually: he's just saying all the awful things he experiences so he can get peoples' reactions and figure out which of those things it's most important to hide. He needs an outlet to do that but I don't think it has to be you.
And if it helps any he doesn't think that he ought to die if he's useless or anything, he certainly wouldn't want useless people to die and his host doesn't - usually - act like they think that, they're certainly good to their own regardless of their condition. He just wants to die in case the god of the dead can help make him better.
I'm really glad he can still be happy about things, even if they're not the things I might like him to be happy about.