Well, I do like the concept, and it sure is a professionally crafted signature.
It's a bit too busy for my taste though. Because of the colours. What I'd suggest is giving the left half a completely warm and dark colour scheme and giving the right half a completely cool and bright colourscheme (including the background).
This will underline the characters's contrary qualities.
Also, maybe try to put another background for the bright half, as an explosion can be associated more with violence than with positive characteristics.
And, well, I don't know if I like the negated character face. I just don't know. Maybe a negated face for the 'bad' half and a normal one for the 'good' one?
And then, maybe place the "Thomas O'Neill, Mercenary" outside of the signature itself, as it is standing out a bit too much where it currently is.
Note that all this is just what I would do, so you probably shouldn't do anything of this, as it's your signature and your new style.
By the way, that latent weirdness reminds me of Orin. Where is he?