Genuinely believing that you are unworthy of living will bring the disease to its fatal stages.

Oh thank goodness he's can't technically die. /)_(\

Gil is out in public a lot, so he'll probably get sick early on. Sorry Funtom regulars, no Gilbert!pastries for a few days. Pretty much everything that motivates Gilbert stems from his guilt, so it'll be pretty bad. But he's a resilient guy, so he'll still be trying to look after anyone else who ends up getting sick. He'd help in any sort of investigation as well if there was enough cause for one.