Betrayal From Within

"Princess Kenny is a two-faced "bitch" just like Monica and Heidi!"

Walkthrough
Enter the Convieniently-Placed-Shop-Before-The-Final-Boss-Battle and stock up on any food items you need. Then, head left to confront Kenny. Kenny's princess music and video from the Black Friday episodes will start, and he will attack with it playing in the background. Defeat Kenny using any means necessary.

After he's defeated, Stan will exclaim "Oh my God! You killed Kenny!" to which Kyle begins to reply with the usual "You bastard!", but Kenny gets back up. He drinks some goo and turns into a Nazi Zombie. The battle resumes. Keep fighting until Kenny uses one of his special attacks. The attack depends on the buddy. Mash the button shown to counter the attack and the next buddy will come to help, and the process repeats. The attacks that go with each buddy are:

Note: Killing Kenny during this part of the battle will not end it. He gets back up and it continues. Instead of trying to inflict the most damage possible, break down his armor with special attacks like Bull Rush or Circum-Scythe.

With all four buddies now tired, its all up to you and Cartman to stop him. Now is the time to inflict damage. Use your strongest attacks until Kenny falls for the fourth time in the battle.

He still gets up through. There's only one option: to break the gentleman's code. Cartman holds Kenny and orders you to fart on his balls. Eat a mana potion if you need to and use any of your farts on Kenny.

A light will fly out across town, turning the Nazi Zombies back to humans. You, Cartman, Stan, and Kyle go to Stark's Pond and toss the Stick of Truth into the pond, so no one will be driven to madness like Kenny. The guys wonder what to do now, and ask you. Press the button to finally speak. You say Cartman's famous line "Screw you guys, I'm going home." and walk off. Cartman calls you a dick and Al Gore as ManBearPig peaks out from behind a tree before the usual South Park credits roll. Afterwards, more credits roll, but they are skippable. You wake up in your bed the next day.

Congrats! You've beaten South Park: The Stick of Truth! Now its time to finish those Side Quests and work on those Achievements.