If you want to restore order and fear across the galaxy, you’ll have to take on quite a load. Yes, it’s a heavy burden for one jedi/robot to carry, but somebody’s got to do it. Then again, this may just be punishment for turning to the Dark Side in the first place.
“Darth Atlas” by Chris Kawagiwa shows Darth Vader as Atlas kneeling with the partially-built Death Star up on his shoulders. He’s got the whole world in his hands.
Bonus: Check out a video of the creation process below: