the baron isnt an easy task. he has tremendous health, well to do stratagy (on heroic especially), and most of all the mind altering abilities, that of the pyscological class you may be as sonny.
-holdout stratagey- description - the barons health is high, that means his hits are lower than appearing, using the "holdout" stratagey will be your best bet, if you are using a "tank" (high vitality) hydrolic class.
step1. use your debuffs early, keep the baron on his feet, he will figure out your stratagey if you do the same thing. make roald (the human)a tank aswell. make veradux a balanced syled medic, keep them both on defensive the whole time (tactical may be as good with armor variations)
step2. if you can attack the barons focus (or "mana" you will not lose, his whole "high life" advantage is disrupted when he loses too much focus, as he gives up about 5-10 thousand health for focus at times
step3.sit and watch him crumple while you attack his focus, the baron defeats himself
when i fought the baron (took me many tries) i had veradux on phalanx, which means he pretty much only heals. I put that other guy (whose name i cant remember) on aggressive. I am a physcologist, so i used my most powerful spells on him. when i needed more focus, i just used that reguvenate thingy spell, and defeated him. took forever. i dont know if this was helpful. good luck.
Psycho - Traumatise and Haunt Bio - You're laughing. Disrupt him to death. Quit and reload until you get the Unholy Runeblade if you want: It's that easy. Hydro - Regulate.
Psycho - Traumatise, haunt, traumatise again, electric storm for focus if you want, when he gets to 5 or so focus, dark echos, implosion. Fit in an insecurity if you want. Boom, dead baron! On easy...
Bio - ...just do obscure's...
Hydro - Either tank him, and unfortunately pooch didn't provide much detail...have ice wall, a glacier or 2 if you want, restore, and dead man's plea, and of course regulate. Spam regulate, when someone gets tick tocked ONLY, ice wall them, then dead man's plea veradux, restore them if you wish. Risky, but faster than... The freeze lock way, all you do is flash freeze, regulate, flash freeze, regulate, mind freeze, 2 regulates, mind freeze, 2 regulates, and repeat the cycle. Mind freeze the Baron when he uses Deep Burning too.
As a psycho you could try the shock coma retrograde trick...which was...shock coma, lots of high voltage, retrograde? Was fixed though, but you should take off a chunk of his health...