Keikenchi Chochiku de Nonbiri Shoushin Ryokou

After losing his girlfriend to a brave hero, Toru is expelled from his S-Rank party. With a feeling of sadness and pain in his heart, he defeats a demon he meets outside the city, and his ability [to save experience] is broken! Toru becomes level 300 in the blink of an eye! With this power that far surpasses that of heroes, there is nothing that can stop him.