The Heros party was attacked by a huge band of powerful devils. The party will without doubt be annihilated if this were to be on. One person in the party, the strongest mage, Rakku, made a decision to stop the enemies in their tracks. Leave it if you ask me here and go! But Hey, Ill catch up immediately, alright? Rakku mindlessly defeated the enemies, again and again. Using his special skill, Learning, Rakku learned the devils magic. As he studied and utilised the devils skills such as Drain Touch, he continued fighting, without rest nor sleep. The devils got better and stronger, but Rakku too rapidly grew. Rakku battled for a decade, until no devils came at him. Rakku returned to the administrative centre, and was surprised. His own name became the currency, and a gigantic statue of him, albeit fairly beautified, was erected. Because of him relentlessly absorbing the vitality of the devils, he previously become young again. An appearance unfitting of his age. Godly abilities. I stick out too much Rakku concealed his true identity, and made a decision to pretend being truly a novice adventurer. Rakku, disguising as a F-rank warrior despite as an S-rank mage. His adventure in this now peaceful (?) world starts now!