I didn't mention before, but the thing that I find stupid? It's not that Falta didn't use his powers on his brother, but that he don't use it at all out of work.
Hear me out, dude literally knows how there's a bunch of diseases that can catch you by surprise even with modern medicine, which makes them even more dangerous to the era he reincarnated, if it was me I would be using my power all the fucking time just to make sure nobody is sick, at bare minimum with my family and important people in my life, he literally just need to look at them for a fucking minute to know if there's anything wrong.
Typical shitty japanese writing where they never
really use the powers to its fful potential