Water bears at the beginning, wet bone forest eating old people

(Behind the scenes, cold-blooded, light on Dihua, no heroine, not brainless. If you want to be brainless, please go elsewhere. I am writing about a selfish insect that seeks profit. I will not bow down to Long Aotian.) Gu Zang was reborn as a water bear. He entered the Wet Bone Forest with the All-Heaven Devouring System and fought wits and courage with the Slug Sage. The Slug Sage refused to let him go, so Gu Zang could only gnaw on the bark in the Wet Bone Forest day after day. Just when Gu Zang was about to challenge the old woman Slug Sage again, he was kicked into Konoha...