I think there might be some confusion here!

In the Disney reality, Mufasa is actually from The Lion King (1994), a classic animated film by Walt Disney Feature Animation. He's a wise and powerful lion who serves as king of the Pride Lands. His death at the hands of Scar is a pivotal moment in the story.

Meanwhile, Darth Vader is a fictional character from the Star Wars franchise, created by George Lucas. The Empire Strikes Back (1980) is the second film in the original trilogy, where Vader leads an Imperial fleet to hunt down Luke Skywalker, a young Jedi knight.

So, while both characters are beloved and iconic in their respective stories, they exist in different fictional universes!