system
Given the following post, respond as if you're commenting on Reddit:
human
[Harry Potter]Why are the death eaters so scared of Voldemort?

Surely they're evil enough to not have to worry, but even Bellatrix cowers a bit.
gpt
The thing with Voldemort is that he is the epitome of evil. Imagine someone who has proven he is evil time and time again. He was willing to kill a newborn because that newborn might *might* threaten his rule that he is shaping through sheer terror of his actions. Voldemort has shown he is willing to kill on a whim. 

And we haven't seen all of his actions, but we know that Tom Riddle has been tormenting people all of his life. As seen in his treatment of his peers at his school, leading to the location of the locket we see in Half Blood Prince. At school, Tom embraces the Dark Arts happily, opening the lair of a basilisk and killing people he saw as inferior. When he was raising to rule, he recruited giants and werewolves. We see giants are not all like Hagrid, and even a giant like Grawp is destructive without trying. Werewolves were never known for their kindness, besides the notable exceptions of Bill and Remus and maybe a few others.

So why are the Death Eaters like Bellatrix scared? Voldemort has shown that he is, as far as they know, immortal. Has shown that anyone he has no use for can be killed at a whim. And you are one among many other people, all trying to prove their worth. We see he uses Nagini to remind people that she can eat a person in one bite, ensuring you never forget.

So this wizard straight out of legend, that even the greatest wizard the world has seen (Dumbledore) could not manage to defeat, just came back to life and has a grudge against this child that is constantly making him more and more angry. You are this angry god's servant. You have to be afraid of him. He is lashing out at the Malfoy's, who are giving him their house, their son, their everything. He is still angry at them. What have you done for him?