Damien's soul energy passed through the hound's body to its soul plane. Luna had told him that he can't resurrect dead beings that have been dead for too long since their soul would have already dissipated or if their cultivation is too high as his soul isn't powerful enough to raise them back to life.
The higher the cultivation the dead had, the more soul energy he had to burn to raise them back to life and to at least maintain their undead state for a while. Otherwise, they would immediately die again if it's too much for him.
Even now Damien was struggling a bit as he concentrated his soul energy on the dead hound. But within a few seconds, Damien stood up and said in a deep voice "Rise!"