"Alternate" comic book ending.
If you're interested in knowing how the comic book ends, and how that could relate to potential sequels or future books in the Urban Horror Stories series:
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The final ending of the comic is the same, with Yuan finding a new disciple.
However, the comic elaborates on what happens when he says he leaves Taiwan and travels the world with Yi Jing. In the comic, he and Yi Jing go to different countries trying to track down Hydra. Yuan fights some more of his animated corpses, and then in a final showdown, he actually kills Hydra.
I suspect that in the Author's mind, Hydra will eventually be beaten, although if the speculation on the Chinese internet is correct, it might involve multiple characters from the Urban Horror Stories series.
If you want to check out the comic in Chinese, click here. Scroll to the bottom of the page and you can view the comic issue by issue.