Vitali Klitschko tends to stand out in a crowd. His 6-foot-7 frame, all 240-plus pounds of it, usually towers over anyone around him.
And so if the surging masses wasn't evidence enough, his chiseled head sticking out of it was a sign that Klitschko had arrived at the protest.
"Klitsch-ko! Klitsch-ko!" they chanted, waving the red flag of the political party he founded called UDAR. The name, appropriately, means "punch."
Klitschko is the reigning WBC heavyweight boxing champion. He has emerged as a leading figure in Ukraine's opposition movement and, by some estimates, is one of the most popular politicians in the country. He's a member of parliament and has announced plans to challenge President Viktor Yanukovich for the presidency in 2015.
"Ukrainian political fight is a fight with no rules," he told ABC News with a grin.
His celebrity hasn't hurt his political ambitions, but he has always sought to emphasize he has the brains to match his brawn. Klitschko has a PhD in Sports Science and is an avid chess player, earning him the nickname "Dr. Ironfist."
He has played a visible and vocal role in leading the recent protests against Yanukovich's last minute decision last month to ditch a trade deal with the European Union in favor of a closer association with Russia. That decision was never just about a trade deal. It was a tug of war between Europe and Russia, and a battle between the two feuding halves of Ukraine as to whether it would look more to, the West or to Moscow.
At the opposition headquarters, inside the trade union building which protesters have now occupied for weeks, Klitschko was visibly stressed. Outside the window, the crowd in Independence Square had set up a tent camp numbering around 10,000. Just days earlier police stormed the square, attacking the protesters. At times the crowd has surged to over half a million people.
Foreign officials are frantically trying to broker an end to the crisis, prevent violence, and guide the opposition leaders.
Between meetings with the U.S. ambassador and a delegation from Europe, Klitschko sat down with ABC News recently to discuss the crisis and his political future.
Klitschko called Ukraine Europe's most corrupt country and said its politicians need to change their mindset.
"The mentality and vision have to change because they worry about themselves," he said, spouting off comparisons in economic growth between Ukraine and other Eastern European countries like Poland and the Czech Republic which had long ago embraced reforms and joined the European Union.
He referenced the students who were jailed and journalists who were beaten when riot police stormed the square, asking "Is it a democratic country or not?"
Klitschko displayed a tendency to slip into boxing references when discussing politics, perhaps a reflection of the many times he's been asked about whether his fighting career has prepared him for public life. He suggested that it may take a long time for the protests to affect change.
"It's not one round. It's not two rounds. It maybe 12. I don't know," he said, his English improving as he slipped into canned lines he has recited in the past.
"No fight, no win," he said. "That's why the people stay there."
His wife of 13 years, Natalia, sat next to him, helping him occasionally when his English stumbled. With the crowds echoing outside, she pointed out that many among them are women.
"I know why they are there. It's because I am the mom and I know what every single woman around the world wishes. The best future for the kids. The best future for their own children," she said. "I wish that my kids will live in a European country with a right to speak, right to live a better life."
Klitschko has never been knocked down in the boxing ring. Asked if he can win this time in the political arena, he replied:
"Yes of course. If you don't believe in yourself you never win."