Depends on what you mean by no combat. Do you mean all points into, say, Technical Aptitude, Stealth and Toughness? That's the only way in which you'd have a character who is unskilled at every kind of combat (4 guns, gadgets, martial arts). If that's the case, I'd say:
(1) By going out of your way to create a character which is deliberately and radically poor at combat, well, you're asking for the game to hand you a smackdown;
(2) Having no skills still doesn't prevent you from using weapons; Shadow Operative is king here, and you should have Brilliance as well, which gives you a huge advantage in outmaneuvring Brayko. Stealth to avoid his knives, get behind him, lob an incendiary grenade and explosion grenade (time it so 2nd explodes when his armour is down) and slam assault rifle at him. He's gone.
I haven't done this, since I never made such a character, but once I did beat him on Hard with Stealth, grenades and SMGs alone, with zero skills in SMGs. So it was pretty close, I just had Overclock to help.
In Veteran, I made a character who, by the time I reached Brayko, had maxed out Stealth and Technical Aptitude, while Martial Arts was about halfway in. I couldn't get near him with such skills because as soon as he took out his knives he'd knock off, at the very least, half my health.
And the game was designed for such a character, by the way. It was downright easy, in fact. Except for the boss fights, of course.
If it wasn't for the stealth glitch in that fight, I probably wouldn't have gotten through it. And even then it took ages to ping away at his health with the pistol.