A Travelling Man recommendation if you like a darker twist to your xianxia.
ABSENCE MAKES THE HEART BURN HOTTER
Chu Wanning has slumbered for five years since Mo Ran rescued his soul from the underworld. He wakes to find the world changed-and the greatest change of all is to his disciple Mo Ran. Now grown up, Mo Ran is nothing like the callow youth he remembers, and Chu Wanning finds himself drawn to his disciple with a force he never anticipated.
Meanwhile, Mo Ran has at last set aside the misunderstandings of two lifetimes. When his hatred for his teacher falls away, he finds the feelings beneath are not respect between master and disciple, but fiery passion. Yet even as the two wrestle with their own hearts, Mo Ran begins to realize that this world is diverging from the past life he remembers in strange new ways.