After defeating the zombie baseball players and exiting the dugout, you will initiate a cutscene. Juliet's sister Corellia will be up in the rafters with a sniper rifle. With an acrobatic leap, she will reach your level. After an awkward introduction to Juliet's boyfriend, Nick, they will be interrupted by the next boss zombie in his flying Viking ship. Cordellia will send the both of you flying up to the ship, where Juliet will confront the metal-head boss and his sentient bear jacket.
Boss Battle: Yumil
After trading a few insults and threats, Juliet and Yumil will square off on the deck of the Viking ship. The first phase of this battle will be easy and should be over in a matter of minutes. This portion of the battle follows a simple "attack and dodge" pattern. Run up to Yumil and attack him viciously with your chainsaw, only pausing when he winds up for a melee attack. Hit the O or B button to dodge over the attack and resume striking him from behind. As Yumil's health bar declines, you will soon come upon a quick time event. Mash the saw button repeatedly and quickly to tear straight through Yumil's legs. The boss will immediately take to the air after the quick time event and hide behind the quite massive drum set sitting at the top of the ship, unphased and perhaps even strenghthened by your attacks. He will then summon a group of minions to attack you while he recovers. Flying around on jets of blood that spew from their severed legs, the minions will hover over the stadium as you enter the second phase of the battle.
You will have to use your new grenade launcher attachment to blast the Viking from the sky. Shoot the giant drum set weapon on top of the ship, but watch out for flying legless enemies homing in on your location. They will quickly rush you, one after the other, demanding lightning fast dodges. As you shoot, focus on the sky to see when the enemies begin to charge you.
After destroying the drum set, Yumil will return to the ground to make things a little more personal. He will now attack you with electricity-based attacks, including a melee attack with his staff that will shock you and knock you to the ground if it connects. Mash on either the B or the O button, depending on your platform, to hop back to your feet. Remember, the faster you mash the button, the faster you can be on your feet and sawing into Yumil even more. Nick will urge you to use your Chainsaw Blaster grenade launcher attachment in this section, but it really doesn't matter which weapon you use to take him down. We found getting in close with the chainsaw and doling out heavy attacks to be the most effective way to deal damage quickly, but players who would rather stay at range and try to avoid the electricity attacks can certainly also use the Chainsaw Blaster to spice things up.
Occasionally, Yumil will also rush you with a flying kick attack during this phase of the fight. You will know that he is launching this attack when he jumps off of the ground. When you see this tell, immediately dodge to one side or another to avoid taking heavy damage and having to mash a button to proceed with the fight.
Soon, you should have depleted Yumil's health bar. Approach him for one more hit to initiate the now-standard boss ending quick time event. Mash the saw button to chop the boss in half. This won't finish the fight just yet, though, as you will still have to contend with a third phase, in which Yumil splits himself into two halvves and attacks you from land and air simultaneously. His upper half will hover around in the air and use the starr for quick and hard to dodge attacks, while his lower half hill attempt to kick you from the ground. Occasionally, the lower half of the boss' body will leave the ship, at which point it will wait in the sky around the ship for a little while before coming soaring back at you at lightning speed. Dodge out of the way of the legs and then hack them apart as you recover. The main threat, though, is definitely the upper half of the body, which will be much more aggressive. Attack both halves of the body until Yumil retreats back to his drums again.
As Yumil attacks you from his perch on his drum set, you will have to watch out for a few new attacks, which the desperate boss will throw into the mix in an attempt to confuse or disorient you. The first of these is a lighting ray attack that will beam quickly straight at you. You'll have to have very precise timing to dodge this attack, as it is lightning, and thus travels very quickly. The second attack is a laser beam that will sweep across the deck of the ship, beginning at the far end and making its way towards you at the back. Simply jump over the laser beam to dodge it. Note that you can earn an Achievement/Trophy in this battle by being struck by the lightning attack a few times, so if you have health and lollipops to spare, it might be worth it for those Achievement-hungry players out there.
Anyways, just keep blasting Yumil's drums with your Chainsaw Blaster and he will soon yield. If you need ammo, scour the environment for ammo pickups before turning your attentions back to the boss. When the boss returns to the ground, he will attack you with both halves again. You shouldn't have to hit him many more times before he dies in another quick time event. Even this won't be the end of Yumil, though. A giant version of the zombie's head will hover over the ship and attack you desperately. His first attack will be a sweeping laser that fires from his mouth. The beam has a straight trajectory, so when you see it firing towards one side of the ship, quickly dodge over to the other side. This will prompt the head to come down to your level. The head will bounce around the deck of the ship for a while in an attempt to smash you. Just stay one step ahead of it, and round the corners of the ship to collect ammo for your Chainsaw Blaster. Use the projectile weapon to hit the head as it bounces and flies around the ship. You should be able to kill the Viking with just a few more blasts from the attachment. Kill Yumil this time will end the battle for good.