For those who forgot after the "old monster" ( poison douluo ) kidnapped him he also poison him seeing if he can actually cure poison or if he got lucky with dealing with his granddaughter ( from the royal combat team ) well after running into the ice one by chance, he immediately left to find the fire one almost dying by the poison in the process, after absorbing them he went from burning to turning into ice in quick succession causing ever ending, ungodly pain, almost dying from just that, so he crawling towards/falling into the yin-yang well and barely surviving, after that he basically had poison immunity due to those to plants ( also cure the old monster with some herbs and some of his blood of his blood ) those plants in his hands are those same herb, not sure if he reformed them via blood, or extracting it from his body somehow ( I'm confused on both actually, thought he just gonna use is blood again via cutting ) either way hope he doesn't lose them cause they're godly and bullshit yet understandable plot armor against poison