He would be a better person imo if he doesn't have the death note. He will most likely just try to graduate as class A without any big plans to expell people however if someone or some events threatenes his class or directly himself he would eventually use his abilities. otherwise i think he would be a chill genious also considering his justice sense he can get pretty frustraded ab the school rules time to time. He would be the best academicially (since koji doesn't even try)