Horrifying Wedding Night, I Was Taken to the Mass Grave by the Snake King

Eighteen years ago, my grandfather killed a big snake that was about to turn into a dragon. The next day he was found hanging from a crooked tree. Eighteen years later, a black snake found me, and from then on my family and friends suffered bad luck. He said that he wanted me to continue his family lineage, and as long as I abide by the agreement with him, he would let me go. Who knows, all this is just a bigger conspiracy...