The Great Jahy Will Not Be Defeated! Ep 4 F2F transformation
 

Saurva, a resident of the Dark Realm who has long sought to usurp the role of second-in-command from Jahy, looks for a chance to defeat her with a magic intensifying potion, only to accidentally feed it to a dog instead. The next day, Saurva uses a magic pill to take Jahy's form in an attempt to ruin her reputation, only to wind up inadvertently improving it instead.
YouTube Link: https://www.youtube.com/watch?v=ldNK4vsHCls