Why does Darth Vader operate openly with his Sith name under the Empire, while Darth Sidious keeps his a secret in favor of Emperor Palpatine? Is there an explanation in either Canon or Legends?

Thanks for the advice. But does that make sense from a narrative perspective? I didn't think that the Bounty Hunter character was a Mandalorian.

I'm thinking about creating a Bounty Hunter character, and I've narrowed it down to a couple names that I like. I'm thinking about either Boris, Baurus, or Beor. However, each of these names are taken individually, so I thought I would give my character a last name, sense we can now put spaces in the character creator. The problem is, I can't think of any cool last names befitting a Bounty Hunter, so I was wondering if anyone on the forums could be of help