Caleb hadn't had a good long stare down for a while. Back in Hellfire they'd test your abilities whenever the heck they felt like doing it...there wasn't a build up where they sized each other up beforehand. Also when he faced off against this guy's doppelganger it was all rage I can take down everyone thing. The guy wasn't a waify thing so he wouldn't have to hold back when he went on the offense. Sure he knew most of the testing was his defensive aspect since that is what his power was basically. The offensive skills had nothing to do with genetics.
"Adaptation," he smirked, "Basically whatever you throw at me my body will change somehow to leave me unharmed...or at least less harmed than I would be. I already know your power, I was briefed. Anything else you want to know?" Caleb had a few questions of his own but they weren't really relevant to their fight...it was more him wanting to know if he had a brother...a douchebag brother who had a smoking hot twin sister and who was currently dating his sweet, innocent, too nice for her own good, baby sister.
He cracked his neck, "Just to let you know I will go on the offensive at times and I won't hold back...just want you to know that this fight isn't going to be just you attacking me and me defending myself. I won't kill you but...I won't go easy on you."