"Cancer... That is that tumorous disease, is it not? The kind that is hard to heal even with most healing spells..." Eiro asked with a light, sad frown on his face. Arc immediately nodded his head in response, and looked to the side, "It was... Horrible. It spread throughout my whole body, and I was in complete and utter pain for the last year of my life... At some point, all my friends stopped visiting me in the hospital, and my grandfather, the only family I had left, died and I wasn't even able to go to the funeral."
The moment that Eiro heard this explanation, he realized something, "And you wished you wouldn't be able to feel the physical pain from that disease, or the emotional pain from being all alone. When you died, that wish was fulfilled."