Baron Brixus is not hard at all. Haven't tried Psychological yet. Basically, take down his focus. If you can't, then tough it out. At the beginning, you should have at least CONSIDERED getting healing, buffs, or something hurting your enemy's focus! Trust me, they are still useful after the Baron. Wait until he weakens himself, then hit hard. Your ability bar should generally comprise of a focus regen move, a couple of hard hitting moves, a stun move, (To Heal), and healing/focus drain moves.
