Seven Horned Serpent

Description
A legendary poison serpent located in the Yunnan's Poisoned Blood Valley. Its seven horns are indestructible and can't be scratched. Found and killed by Joo Seo Cheon, the core of the beast was used to advance his poison arts mastery from 10% to 20% evolving his hundred poison immunity to a thousand poison immunity. Using the reminder of the energy, he was able to enter Unrestrained realm.