Despite his best intentions, Iron Man made a few questionable choices during Civil War. This seminal event forced Tony Stark to make some hard decisions, many of which turned into big mistakes. However, being a hero at heart, Stark has taken steps over the years to redeem himself in some way.
Iron Man's quest for redemption began after Invincible Iron Man #24, by Matt Fraction and Salvador Larroca. By the end of this storyline, Tony had rebooted his entire brain, with no memory of anything from Civil War. So many mistakes were erased from Tony's mind, including hunting down his fellow heroes, placing them in the Negative Zone and even cloning a new Thor who was responsible for the death of Goliath. Practically reborn, Iron Man built himself a brand new suit of armor and moved ahead into the future. Tony also started a new company which he dubbed Stark Resilient, based in Seattle. Stark Resilient was more focused on renewable energy sources than weapons manufacturing.
One of Tony's first big inventions was a car with greater fuel efficiency based on repulsor technology from the Iron Man armor. Of course, Stark Resilient still faced competition from other companies like Hammer Industries, led by Justine Hammer. Stark's new car experienced attacks from a horde of drones and a new "hero" named Detroit Steel. Even so, Tony took this all in stride and managed to come out on top.
Unfortunately, Tony relapsed into drinking again, which was detrimental to his mental health. Moreover, this struggle of alcoholism was used against him by The Mandarin, who returned to destroy Stark's livelihood. The Mandarin used several small time villains to manipulate Tony so it would appear that he was fighting while drunk. The villains also tampered with Tony's repulsor unit, disrupting his weak heart. After almost forfeiting his tech to the government, Tony seemingly relinquished his role.
In truth, Tony had entrusted the role to War Machine, asking his best friend to fake his own death. From this point forward, Tony began playing things pretty close to the chest, isolating himself. Iron Man took a leave of absence from the Avengers and resigned from Stark Resilient without any explanation.
None of Stark's friends knew what he was up to before he was captured by The Mandarin. The villain controlled Stark's body from the inside, forcing him to build Titanomechs for him for several months. Fortunately, while in captivity, Tony convinced some of his foes to rebel against The Mandarin, before they all worked together to destroy the Titanomechs.
Overall, Tony did a lot of good work during this era, with all of the right intentions. Achievements like his fuel efficient repulsor tech, rebuilding Asgard and building a company that could exist without him were some of Stark's finest works. Still, when things got tough and The Mandarin attacked, Tony was backed into a tight corner.
With few solutions available, Tony's company, armor and even his body were left compromised. Iron Man had to make a lot of tough calls during this time, which isolated him from friends and allies. These decisions certainly weren't as bad as those he made during Civil War but they did cost him a lot personally. Rhodes and Tony lied to their friends, Tony had to leave his company behind for a while, he clashed with the US government and even worked for The Mandarin for months. It is perhaps because all of these questionable tactics that Tony remains a compelling character. Iron Man always has the best of intentions, creating new technology and seeing a better future.
Tony tries to do the right thing, and when large threats like The Mandarin appear, he tends to make big sacrifices for the greater good. Tony's fears and anxieties about the future make him very relatable, since they lead him to make mistakes along the way. Iron Man is a lot more human than several other heroes, facing his own personal ups and downs. The important thing, however, is how Tony gets back up and tries again. It's this earnest attempt to be a better person that makes Iron Man a true hero.