Who was the father of Tanjiro, who was in Ghost Blade? Why was he able to reach the " transparent state "?

The father of Tanjiro in 'Blade of Ghost Annihilation' was a member of the Ghost Hunters called Daisuke. He had outstanding combat ability and keen insight. At the same time, he also had a unique thinking and judgment ability, which was called the "transparent realm". Daisuke had reached this level because he was constantly growing in battle, accepting all kinds of challenges and training, and constantly learning all kinds of knowledge and skills. His combat skills and thinking ability had been greatly improved, allowing him to better deal with various situations and make the right decisions. In addition, Daisuke also experienced many events and tests, such as a life-and-death struggle with ghosts, parting with relatives and friends, and a life-and-death struggle with enemies. These experiences not only made him stronger and braver, but also made him more mature and wise. That was why he was able to remain calm, decisive, and intelligent in the face of all kinds of difficulties and challenges. He became a solid backing and an important mentor for Tanjiro.