At the height of the Greek debt crisis, he crossed swords with German nemesis Wolfgang Schaeuble, who demanded drastic austerity in return for financial aid.
Four years later, the former Greek finance minister Yanis Varoufakis is running in European parliamentary elections -- in Berlin.
The iconoclastic, motorcycle-riding 58-year-old economist is running a political stealth campaign, with few major public events or media engagements.
However, favourable electoral rules may allow him to be elected to the parliament in Strasbourg.
Varoufakis "meets the conditions to be a candidate in Germany, he is registered in Germany where he has a residence," says a member of his team.
The law here demands that a candidate for the May 26 election must be a citizen of a European Union country and have resided in Germany for at least six months.
- 'Political monsters' -
Varoufakis as minister for a little over five months alienated many of his European colleagues with his outspoken style, academic tone and activism on social networks.
Now he leads the list of Democracy in Europe, a German political party that is part of DiEM25, the anti-establishment movement Varoufakis helped to launch in early 2016.
He says he now has nothing but "contempt" for the head of the Greek government, Alexis Tsipras, whom he accuses of having reneged on his far-left Syriza party's electoral commitments.
His new grouping is "the first serious transnational and progressive movement" in Europe, argues Varoufakis, who has outlined its vision in a handful of interviews, public meetings and short videos on social networks.
The party demands greater transparency in politics, including live video streams of European summits and meetings of the European Central Bank, the institution many Greeks blame for the biting austerity policies of recent years.
His party advocates a "Green New Deal" with large investments in ecological projects, and Varoufakis has also called for the establishment of a Constituent Assembly to build a more democratic Europe by 2025.
"As a convinced European, I protest against what the European institutions are doing," he has told Deutsche Welle TV, pointing to the rise of far-right parties and raising the spectre of the 1930s.
"They create discontent, and this produces political monsters like Matteo Salvini and the League in Italy, the AfD in Germany, or the Golden Dawn in Greece."
- Candidate in Greece -
So why is it that the man whom Germany's top selling daily Bild labels the "Greek clown" is running for election there?
Officially, this aims to signal that there is no "struggle" between Germany and Greece, between Europe's "north and south".
Another consideration may be more pragmatic: Germany's rules for the European election do not have a minimum threshold, heightening chances for a party that is polling at around one percent.
In 2014 European elections the satirical group Die Partei was able to send a representative to the legislature with only 0.6 percent of the vote.
In other EU countries, including Greece, the threshold is three percent -- a more daunting hurdle for Varoufakis, whose political star has dimmed in the years since he quit his ministerial post with a simple tweet.
He recently told the Frankfurter Allgemeine Zeitung that, if elected to the European Parliament, he wants to voice his ideas and then quickly hand his MEP post to a party colleague.
He told the daily that "voters appreciate politicians who are honest and transparent and who say 'Look, I'm not doing this for the career or salary, I don't want to enter the European Parliament for the limousine and 10 staff".
After bowing out in Strasbourg, he says, he plans to return to Greece and run in parliamentary elections there later this year with the movement he has created, Mera25.