I looked at some super-heroes, anti-heroes and super villains and collated some of the best and most inspirational that I came across. The main features that stood out were thematic powers, names and outfits as well as lots of tight-fitting suits! Included are a few merged super-characters such as a ghost-rider/iron man, bat/spider man, etc.
I decided that after getting a good idea of the themes, I needed to narrow it down to a short-list of characters to create my merged super-character. I was thinking along the lines of something dark, magical, maybe demonic or possessed.