What Ianto's getting from all of this is 'don't associate in any way with Aziraphale, because then you'll enter the murdersphere of Lucifer'. There's obviously a lot of preexisting drama there he doesn't want to get in the middle of, or even on the sidelines of. He had a very minor death wish, but that's all cleared up now, probably, so the Devil and all of this is very close to the top of his list of things to avoid.

He wraps his hands around his mug of coffee and inhales the smell, wishing desperately that it were real and that he was allowed to have coffee in hospital. And that they would provide him with the necessary coffee-making equipment, because there's no way he's drinking hospital coffee. "Have you heard of the Doctor? Should get in with him. He's a 'do what needs to be done' type. Fixes the unfixable." Ends justify the means, hurt your companions for their own good, etc. A dark look flits across Ianto's face. "Bet he'd love your Lucifer problem."