First off, this could be seen as a request for help with a conversion of something from the MMORPG "City of Heroes" which you can only get by getting one of your heroes to level 50-so if this is in the wrong place here on the boards, please tell me where to put it and I'll make the adjustments.
I think that the idea of the Kheldians AKA "Peacebringers" and "Warshades" actually have more of a place in the Champions setting as opposed to the one for "City of Heroes". In order to survive on Earth, they have to merge with a living host and sometimes this host is a powered being (someone with powers of any sort) and sometimes it's just J. Random guy on the street.
A good reference material that I found for them is at the following link:
http://db.gamefaqs.com/computer/doswin/file/city_of_heroes_kheldian.txt
Anyway, before I start to ramble off topic-I'm thinking about seeing if this can be done in Champions but the problem is I don't have the first and faintest idea on how to stat it creation wise but I do have the IC background written up and oddly enough I've found a way of doing it rather interestingly within already established materials such as the "unknown entity" that merged with a young sailor/painter who would become Helios of the Protectors (from "To serve and protect", one of my favorite modules from the older system).
If anyone can help me with this, I will gladly return the favor by helping with writing and such in return.