In the first boss fight, you'll go up against the very short tempered Big Bull. Bull is actually quite a difficult opponent if you go up against him blindly. Knowing what works against him and timing it right will ensure a swift victory though.
First and foremost, Bull is very weak to Jack's Heavy Chainsaw attack. One hit from that will take a big chunk of health from Bull. Remember, since the heavy attack requires two bars from the special attack metter which has four, you can do up to two chained attacks that will eat away at Bull's health. He does tend to block quite a bit however if you hit him with a heavy attack while he's blocking, that will usually send him into a stun, leaving him open to attack.
Another thing to remember is that Bull's attacks can be parried with a well timed grab. When you see him charging up at you, a grab will cancel his attack and deal some pretty good damage as well.
Twice during the fight, Bull will jump away and unleash his minions on you. This is a good opportunity for you to restock on health in case Bull managed to hit you a few times. The minions aren't at all difficult and usually go down with a good hit or two.
When Bull's health reaches half, it's time to unleash Jack's Rampage. This will once again let you unleash attack after attack with your chainsaw without the penalty of using up your special attack bar. That means spam that Heavy Chainsaw attack like nobody's business.
This technique should ensure a rather painless victory, and Big Bull will now be unlocked as part of your roster.
