Ran'ei Divine Master, his true identity should be the teacher of Sword Master Cold Crow, of course, that's another name, Tengu Divine Master.
According to Sword Master Cold Crow, the exceptionally talented Tengu Divine Master had altogether cultivated the six major branches of the Tengu Shrine at that time.
If he had been given more time, he might have been able to complete the cultivation of all eight major branches, thereby elevating his strength to a peak never before reached by anyone.
However, it's a pity that because of the decisive break with Sword Master Cold Crow, the aged Tengu Divine Master was killed, but he must have been prepared for this long ago.
Although his physical body was destroyed, he continued to exist in another form.
And Ran'ei Divine Master can be regarded as a fraction of Tengu Divine Master's many memories and strength, though not complete, and his strength cannot be considered top-notch.