A brief description of the Vermeil in Gold – A Magician Pushes Through the Magical World With the Strongest Disaster manga:
Alto, a student of the school of magic, who was on the verge of staying for a second year. He accidentally found a book that activated a magic circle and summoned the sealed devil Vermeel as a result! Vermeil is a very unhealthy personality in the form of an older sister and with a force destructive enough to be called catastrophic! He has a long road ahead of him in the world of fantasy, in which the wizard walks with the strongest creature in the world.