Cultivation. Magic. Empowering unwitting animals! 
A thousand-year-old cultivator, Drew, is about to ascend to a higher existence. As he begins the process, he finds out he has pissed off one too many demigods. Though he manages to fight off the concerted effort of sect elders and patriarchs...he is slapped away from the higher realms by something. 
After an instant or an eternity, he awakens on a lower realm! The air is filled with garbage energy, and his emotions of all things are allowing him to control it. For a cultivator that has spent his existence absolutely controlling his thoughts...that won't do at all. To regain his place in the cosmos, he will need to create the energy his is familiar with once more...even if it might poison the entire world. 
Then again...he could just take it easy and leave all the hard work to his 'willing' apprentices.