

So I looked into this more and basically Darth is a title given to sith lords, others have had it like Darth tyranus and Darth sidious, but here is the kicker.
Darth Vader’s fatherhood was only conceived of after the character was introduced in empire strikes back, so the name was not necessarily related to fatherhood in the story and the only reason I could think of for it existing is just because it sounded cool.
A possible reason could be that Darth is a combo of dark and death and Vader is possibly short for invader.
Otherwise I’m not sure if there is any clear reason for the name that is undeniably the reason for the name.
Here’s hope to ladybird, it seems like a recipe for good things but its still like a year out if I recall for a beta release or something