With the 8 chapters I currently have of Operation: Vindicta, Rauera definitely seems the most powerful. In chapter 4 of the story, Stoax, Minera, and Rauera face an attack from a squad of SON troopers. The troopers used a tank esq vehicle that can shoot barrages of protodermis spheres, in which Rauera managed to do the following
"Suddenly Rauera bursts into the scenario with a chokutō (Japanese straight sword) and proceeds to jump at it, his blade alit with fire. Astoundingly he manages to split the sphere down the middle and lands safety on the other side of the rock wall, the sphere blowing up above him."
Basically, an OVERSIZED sphere of protodermis was shot at the trio but Rauera managed to leap up, split it straight down the middle with only his sword, and landed safely on the other side while it exploded.
Stoax also had his moments of luck too. During another attack from SON troopers, Stoax managed to take out an entire wave of soldiers surrounding him with the help of a plasma wave unleashed from his pick axe.
Pligurius is also powerful, strategically speaking, in that he manage to successfully lead a raid on Arthaka, though also for reasons yet to be explained.