You know, it's absolutely alright if you're doing something that's "taken." As you keep working on it, your characters and story become your own.
Take, for example, the shows
Firefly and
Cowboy Bebop. Both are scifi/western/action series with an ensemble cast of bounty hunters as they go on a new mission or adventure. The two shows are so different from each other in terms of content, style, tone and characters that I'm having a hard time comparing the two.
So if you have an idea, don't worry if you find out that something's already been done. The Phantom of the Opera, the Spirit and Tuxedo Mask all have similar costumes but are very different characters altogether. So when you find out about these things, don't panic. Stay true to your character's personality and wants, and with what works for your story.
As for names...thesaurus.com can help
in one search I found the word "Eidolon," which, by way of wikipedia, means "the astral double of a living being; the phantom-double of the human form." Sounds kind of appropriate in this circumstance...
Oh, "Eidolon" was the name of some one-off guy who died in a semi-obscure western comic, and his name didn't fit the character all that much anyway. So you're good there. XD