Jiang Wu

Jiang Wu is a heart demon created from Qin Qian Xian's obsession with Lu Zhao Yao. Through medication and meditation Qin Qian Xian was able to expel the demon from his heart, but it did not cease to exist. Absorbing negative energy from fear and death, Jiang Wu was eventually able to take steady form. He rescued two dying soldiers, Xian En and Song Yi, and formed a bond of friendship with them. Together they increased his power and eventually took over Mount Xin Sect. After that he set his sights on Wan Lu Sect.

Jiang Wu is carefree and loves making trouble. He encounters Lu Zhao Yao (in Qin Zhi Yan form) and falls for her. Later he meets her again when she has regained her own form and recognizes her, becoming even more obsessed with her.

(Source: Lady_Dragon at MyDramaList)