I know he was really jealous of his sister, but maybe he could just tell his parents directly about how SHE gets prioritized in everything. On the other hand; what he did was too far fetched, so feeling bad for him was dashed out by his cruelty and ill wishes. Maybe fate thought of punishing such a person; because if this boy grew up like that; without guilt or remorse, only selfish desires(though you partly can't blame him for the desires part except the "I want sister to die desire of his") he's just going to be worse.
I know he was really jealous of his sister, but maybe he could just tell his parents directly about how SHE gets prioritized in everything. On the other hand; what he did was too far fetched, so feeling bad for him was dashed out by his cruelty and ill wishes. Maybe fate thought of punishing such a person; because if this boy grew up like that; without guilt or remorse, only selfish desires(though you partly can't blame him for the desires part except the "I want sister to die desire of his") he's just going to be worse.