Where did the protagonist obtain such powerful magic power that he fell into a deep sleep?

The protagonist obtained a very strong magic power in a ruin and fell into a deep sleep for a long time. The protagonist had a friend who lost him in the snow mountain when he obtained the power. After that, he searched for him for several years. This question has been asked for a long time, but no one knows. I'll be more detailed. At first, the protagonist seemed to be staying in a woman's house. The woman's father took care of him. The male protagonist liked the woman. Later on, the woman became a saintess and fell in love with a paladin or something. In the end, the male protagonist's heart died and he left the host's house to explore the world by himself. Later on, he met a friend and saved a woman (princess) during an adventure. Then, he entered some ruins or temple. In the end, the male protagonist and his friend were separated. Then, he inherited the power of a Grand Magus or something like that. After about 20 years, the male protagonist woke up and found that his hair had turned white. He went on an adventure and passed by a small town. He met the daughter of the Holy Maiden and the Holy Knight and the son or daughter of the friend he had separated from before. Then, they waited for something that seemed to be a monster or a werewolf attacking the town and summoned a powerful fire monster. This monster was very familiar with the Grand Magus who had inherited the magic power. Later on, a woman thought that the male lead had disappeared because he had summoned such a powerful fire spell and would suffer a backlash. His previous friend married a princess and became a king. The person he met was his friend's daughter…He forgot about the name of the male lead, let alone the book and wine. Uh, does anyone know what novel this is? A novel from a long time ago It's not called disappointment or anything