Leon Chapter 5 is the final chapter of Leon Story in Resident Evil 6. Having been infected by Carla Radames and abandoned by the Family, Simmons became a monster whose only intent is killing Leon. In order to escape Lanshiang, Leon and Helena have no choice but facing him head-on.
Following a group of surviving BSAA members, the two agents managed to reach a safe area where the C-Virus gas didn't reach. However, the entire city has been overridden by Zombies and B.O.W.s, making survival nearly impossible.
Just as a large group of Zombies closing in on Leon and Helena, the real Ada Wong suddenly appeared with her chopper, ready to give a brief assistance to them. Leon and Helena eventually finds a BSAA helicopter after dodging lots of zombies and explosions. However, the dead helicopter's pilot had been infected and attacked Helena, causing Leon to lose control over the helicopter, which crashed into the Kwung-Lung building. Barely survived, the two agents encountered Simmons, who by all accounts still alive. Driven by madness, Simmons mutates into a dinosaur-like B.O.W. with the intention of devouring them both. Again, Ada is present to help Leon and Helena to fend him off. Together the three of them managed to bring down Simmons. Ada proceeds by heading to the roof, while Leon and Helena follows her via an elevator.
The elevator Leon and Helena are in suddenly explodes, forcing the two to climb the building on the elevator's supporting cables. It turns out that Simmons is still alive. Reverting to his centaur form, he assaults Leon and Helena, while Ada once again help them, and even at one point sacrificing herself to the enraged Simmons. Leon comes down to help her, but was knocked to the edge. Ada saves his life by stabbing Simmons on the belly and let Simmons falls to the debris. Ada uses her grapple gun to escape.
Following the events, Leon and Helena discovers that Simmons is once again remains alive. Absorbing the bodies of zombies around him, Simmons mutates into a giant, grotesque housefly. Noticing that Simmons is attracted by a zombie with an impaled lightning rod, the two agents uses the rods to make Simmons absorbs zombies with the lightning rod to summon thunders to damage him. As the two proceeds to the helicopter left by Ada earlier on, Simmons rises up again to deliver one final blow.
Leon and Helena uses a rocket launcher left by Ada to blow up Simmons, finally putting him down for good. They soon discovers that Ada also left behind the evidence of Simmons' crime. The two then use the helicopter to leave the burning tower.
Chris: "Leon!? Leon, are you all right?"
Leon: "Yeah... But things just got bad. Real bad!"
Chris: "Damn it!"
Leon: "Chris, listen to me. I need you to rescue two hostages from an underwater oil field. Agent Sherry Birkin...and Jake Muller. He's Albert Wesker's son."
Leon: "Chris, he's got antibodies for the C-Virus."
Chris: "I got it. On my way."
Leon: "Good. Thanks."
Chris: "Leon, wait. There's something I need to tell you.
Chris: "Ada Wong is dead."
Leon: "Copy. Sherry and Jake need you. Don't let them down."
Helena: "Are you OK?"
Leon: "Let's just find the survivors and get the hell outta here."
- Insert walkthrough here