Trying to find a name of a manga about a magic user. After taking a water magic test he discovers he has weak magic and after a few years he dies. He gets reincarnated as his descendant living in the country with his mother, due to his father and the other women married to him disliking him for being weak, but he has a vast amount of magic making him god-like.
The main character was considered one of the most powerful magic users in the country. One of the other powerful mages creates a test to determine compatibility with types of magic where you put some hair in some magic water. The main character then found out he had no compatibility with any of the elements. Then he dies and is reincarnated as one of his descendants. Once he remembers his past life, he tests out his magic. He then finds out his magic is as powerful as it was in his previous life, despite still having no compatibility.
His father is a powerful sorcerer who is never around and has another woman as his wife, along with 9 other concubines. He lives in the country with his mother. The two of them both lack compatibility with magic, and are looked down upon.