“Willpower” is kind of a vague concept. Perhaps being able to always do what you think you ought to do? In that case, the downsides would perhaps involve problems of rationalization, or weaknesses in his reason, creating mismatches between what he thinks he ought to do and what will actually produce the best consequences. Maybe his laziness, squeamishness, and fear actually would prevent him from doing things he thinks he should do, but which actually would produce greater harm that he doesn’t anticipate, or his anger, lust, etc. would motivate him to do things with beneificial consequences he doesn’t anticipate, and so he ends up worse off when all that gets overridden.
“Willpower” is kind of a vague concept. Perhaps being able to always do what you think you ought to do? In that case, the downsides would perhaps involve problems of rationalization, or weaknesses in his reason, creating mismatches between what he thinks he ought to do and what will actually produce the best consequences. Maybe his laziness, squeamishness, and fear actually would prevent him from doing things he thinks he should do, but which actually would produce greater harm that he doesn’t anticipate, or his anger, lust, etc. would motivate him to do things with beneificial consequences he doesn’t anticipate, and so he ends up worse off when all that gets overridden.