> the man eats animals alive, corpses at the morgue, drinks blood from hospital patients, and all other kinds of stuff, but people around him judged him to be completely sane?
Those are all normal things to do when you're hungry.
> Also... do you feast on corpses when you're hungry?!
There are many recorded cases of parents eating their child's when hungry such as Bengal famine, holomodor, Armenian genocide and other Tsarist Russia famines, so yeah, when driven people can eat not only corpses, but their own children corpses
There's also the case of the Uruguayans stuck in the Andes after their plane fell and facing starvation they ate the bodies of dead friends whom where on the plane
Those are all normal things to do when you're hungry.