In fact, in the game, we will encounter the skill combination of Tiantian Xuan Doubulu from time to time. In fact, there is no need to worry, just these few small steps can solve this problem.

Dragon Roar, Blue Flash, Iai Slash, Storm Sword Dance
Iai Slash can provide a range attack and can output higher damage during combat.

All ultimate moves are retained , as well as some skills with relatively high attacks, such as Divine Speed and Void Slash.
The BOSS in the later part of the game is relatively difficult. You can't defeat it with different skills. You can only use your ultimate move to smash it and keep moving.
