Backlash is the immortal Marc Slayton, one of the core members of the U.N. crisis response unit: StormWatch and leader of the covert insertion unit: WildCore.  Slayton is a soldier first, a classic war-horse, whose military career (before and after becoming a 'Super Powered Being') is quite impressive and lead him all over the world on different assignments.

POWERS:
Mist

As you might imagine using this ability takes quite a bit out of Marc so he tends to save it.

Energy Coil
 
The reason for his name, Slayton can project (and control) 'psi' based energy coils which he uses as a whip or a solid projectile.

TEAMS:
StormWatch.

A founding member of the U.N. Crisis Response unit Marc Slayton quickly takes on the role of trainer which removes him self from the field for the most part. 

WildCore

It turns out Marc doesn't like not being in the field, he is after all usually the oldest soldier in the room anywhere anytime being an immortal.

ACTIVITY REPORTS:
Wikipedia
Wildstorm Wiki
Comicvine
DeviantArt

A duo is kind of  strange beast when you think about it.  It's a fine line between success and stepping on your partners joke, taking their spot light, or running off with all the fans but when two people have chemistry magic is made over and over again.  Because of this most creative endeavors avoid duos.  Most music bands have more than two members.  Most television shows have more than two central characters, as do most movies.  Most genre of novels star fewer, or greater than, two characters. Same with comics.  Of course when it's done right (Music: Loggins and Messina, Television: The odd couple, Movies:Laurel and Hardy, Novels: Holmes and Watson) then the magic happens.  The same thing can be found in comic books...

 
Much like Romeo & Juliet, Etienne Navarre & Isabeau d'Anjou, Gambit & Rogue Dick and Barbara work so well together they can never really settle down together because that would be the end of the professional relationship and therefore the end of Nightwing and Oracle.  The world needs them, so they choose not to give in to their own personal needs for the greater good.  This dramatic tension makes for great storytelling.

Backlash & Grifter.  Never heard of them?  The old war-horse and the con man, each the very essence of the archetype they were created from, are flip sides of the same coin.  Honor, duty, strength, drive, justice.  Both of them seek it but how is where they differ.  It's not as simple as black & white or dark and light, not when you've seen the things and lived through the things that these two men have (military super soldier programs, beastly mutations, mind control, genetic breeding stock).  This dramatic tension makes for great storytelling.

While the first incarnation of Powerman & Iron fist was a little different this new incarnation is equally good.  The mystical Kung-Fu warrior Iron Fist, cultured and experienced of the ways of the world and superheroing takes the newly minted Powerman under his cowl to train and develop the younger man.  From Powerman's perspective they truly are "Heroe's for Hire" (even though there is a different comic book called that now) as the younger man uses his wages to assist his mother in pulling them out of poverty, the very place Iron Fist and Powerman spend their time fighting crime.  This dramatic tension makes for great storytelling.

Come on, do I really need to make a statement here?  We're talking Chocolate & Peanut Butter, Franks & Beans, Carrots & Peas, they all pale in comparison of the original pairing on the mouths of babes all across the land: Batman & Robin!  I chose this version of the duo because it represents exactly what I feel is best in both characters.  This version of the Batman is the driven tactitioner, a military general on a mission he won't be deterred from.  He's a mentor, a teacher, and a beacon to his troops.  This version of Robin is smart, cunning, self motivated, adaptable, and a great resource for the Dark Knight.