Reincarnation Of The Unrivalled Time Mage

one day at the sorcery academy at the borderlands, broke student avis was forced to win against a genius at the academy otherwise he would be expelled. it’s said to be an impossible feat for him. avis raises his blind and frail younger sister by himself. he goes through the necessary training to get past his insufficient scholarship. but he doesn’t get any stronger, and eventually collapses of exhaust. but at that time, he sees a strange dream. in the dream, he sees the grand sorcerer who used the legendary [time sorcery] that had been used to defeat demons and is no longer present in the current ages. and after avis awakes from the dream, he realizes that the legendary [time sorcery] is his own–!?]