More specifically...
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! :D 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...