Sorry, I meant edge, not karma.
Still, that character build is entirely not a problem. Let the troll munchkin have his power fantasy, he's just as susceptible to bullets, assault cannons, magic and mono whips as everyone else.
Considering I have very rarely seen an NPC or PC take an attack with a 11+ DV weapon and live, this guy doesn't do anything that can't be accomplished by another weapon. He certainly won't be ending fights by himself with his low reaction, and I can't see his melee dice pools starting much higher than 16.
His biggest asset is that he's too big to ignore, and he certainly isn't limiting out his attacks.