Ep 15. Heinous

Star vs. the Forces of Evil is an American animated television series created by Daron Nefcy and produced by Disney Television Animation. The show follows the adventures of Star Butterfly, a magical princess from the dimension of Mewni, and her best friend Marco Diaz, who uses her wand to fight evil forces trying to take over the multiverse.

In season 3 episode 15, titled "Heinous," Star and Marco are on a mission to stop a new villain from wreaking havoc on Mewni. The episode begins with a flashback to when Star was a child and her parents hired a nanny to take care of her. The nanny, who goes by the name Miss Heinous, is revealed to be the new villain that Star and Marco must stop.

Miss Heinous has a vendetta against Princesses and has been on a mission to destroy them. Star and Marco are joined by Queen Moon and her husband, King River, as they try to stop Miss Heinous from executing her plan. The group heads to St. Olga's Reform School for Wayward Princesses, former school of Miss Heinous.

Upon arriving at the school, the group discovers that something is amiss. The school has been completely transformed and the students have been brainwashed to follow Miss Heinous's orders. Star and her friends launch a full-out attack on the school, using their magic to fight off Miss Heinous's army.

As the battle rages on, it becomes clear that Miss Heinous has a powerful weapon that could destroy all the Princesses in the multiverse. Star takes charge and leads her friends into the heart of the school to confront Miss Heinous. She uses her magic to try and take down the villain, but Miss Heinous is too powerful.

Just when it seems all hope is lost, Star has a realization. Miss Heinous is not who she seems. In a surprising twist, Star uncovers the truth about Miss Heinous's past and discovers that she may not be evil after all. The episode ends with Star and Miss Heinous having a heart-to-heart conversation that leaves both of them changed forever.

Overall, "Heinous" is an action-packed, emotional episode that explores the grey area between good and evil. It delves deeper into the characters' backstories and introduces a complex new villain that adds depth to the overall storyline. Viewers will be left on the edge of their seats as they watch Star and her friends battle to save the multiverse.