Ore to Kawazu-san no Isekai Hourouki

Tarou was an ordinary universary student until a strange old magician summoned him to another world, upon learning that his magical power is 8 million, he uses that abnormally powerful magic to revive the old man that caused all this... In the form of a frog. Thus begin the strange adventures of a boy with ridiculous magical power and Kawazu, the former strongest magician, now revived as a frog.