Run. 

That was the last word uttered from the lips of his beloved brother, before Luhan sped off into the veil of darkness. If only, he knew the reason why he had to run,  he would've never run from that terrible scene. But he ran. And now because of him, his brother is dead and the men responsible are chasing after him. 

Chasing, because they knew a secret that Luhan didn't even know himself. 

Luhan is a werewolf.