Battle at Stark Expo

The Battle at Stark Expo was the final battle between Iron Man and Whiplash. Whiplash brought his army of Hammer Drones while Iron Man brought his best friend and ally, War Machine.

Background
Tony Stark throws what he believes will be his last birthday party and promptly proceeds to get drunk whilst wearing the Mark IV armor, forcing his friend Lt. Colonel James Rhodes to don the Mark II armor and subdue him. Rhodes files off with the Mark II and turns it over to the United States Air Force. General Meade orders Rhodes and Justin Hammer to weaponize the suit.

Disgraced, Stark is approached by Nick Fury of S.H.I.E.L.D., who provides him with a chest of his father's old artifacts that can hopefully be used to find a cure for his Palladium poisoning. Reviewing the film reels in the chest, Stark discovers a message from his father that leads him to the original 1974 diorama of the Stark Expo: in reality, a disguised diagram for the molecular structure of a new element. Stark hand-builds a Particle Accelerator with the aid of his computer J.A.R.V.I.S. and synthesizes this new element, creating a new triangular chest Arc Reactor that cures his poisoning.

Battle
At Stark Expo, Justin Hammer unveils his new military drones, captained by James Rhodes in a heavily-weaponized version of the confiscated Mark II armor. Unfortunately, it is soon discovered that Whiplash has complete control of both the drones and Rhodes's new armor, and Stark arrives just as they go on the attack. Stark takes to the skies to get the fight away from the Expo. Rhodes and the Air Force Drones chase Stark while the Army and Navy Drones bombard him from the ground. Stark is able to destroy all of Drones chasing him but is attacked by Rhodes and the two go careening into the Oracle Dome.

Meanwhile, Happy Hogan and Black Widow race to Hammer Industries Headquarters to stop Vanko. By the time they arrive and take the guards, Vanko has already departed for the Expo in a new, more powerful suit of armor, but Black Widow is able to give Rhodes control of his armor again so that he and Stark can fight Vanko together.

The two armored allies get back to their feet and are surrounded by the remaining Drones. After taking out several Drones with small arms fire and hand to hand techniques, Stark uses a laser in his wrist to take out the remaining Drones. Vanko arrives and Rhodes fires the Ex-Wife Missile at him but it is a dud. The two attack Vanko but Vanko uses his whips to subdue them both. Stark tells Rhodes to fire their repulors at each other at the same time causing a massive explosion that takes Vanko down.

Stark and Rhodes approach Vanko who laughs and tells them "You lose". Stark realizes his armor and the Hammer Drones are revealed to have been equipped with self-destruct charges. As they begin to go off, Stark races to save Pepper Potts, rescuing her at the last minute and taking her to a nearby rooftop. She quits her CEO position, and she finally gives Tony a kiss. Rhodes witnesses the kiss and jokingly says they look like two seals fighting over a grape.

Aftermath
At a debriefing, Nick Fury informs Tony Stark that while Stark is "unsuitable" for the Avengers Initiative, S.H.I.E.L.D. wants Iron Man as a consultant. Stark agrees on the condition that Senator Stern present him and Colonel James Rhodes with their medals for bravery.

Trivia

 * There is an alternate ending of this battle where Whiplash found Pepper Potts and held her hostage until Iron Man managed to save her.