What is it about Yanis Varoufakis? We know he’s attractive – in a refinedly thuggish, or soulfully Mafioso kind of a way. And we know he’s clever.

OK, not so clever as to have fixed Greece. Or so clever as not to have been involved in wrecking it, either, maybe. But definitely clever enough to have won himself a cult following, and extensive (presumably un-redistributed) wealth, en route.

He’s pretty hilarious, too – though you might not want to say that to your friends in Athens. Over here, he’s propping up the politics shows, and is well on trend with the chattering classes.

He’s also (if this is different) on trend with the new left: Corbyn has already landed Stiglitz and Piketty; Varoufakis’s invitation must be somewhere in the wannabe-nationalised post.

So, what is it about him? The other night, I went to hear him speak, to try to find out.

Whatever it is, it’s certainly potent: almost an hour before kick-off, the queue of ticket holders (and Socialist Worker distributors) snaked all around the outside of Westminster’s Central Hall.

Inside, the stalls seats filled so quickly that people were annoyed by the management’s reluctance to open the gallery above. ‘‘If we can’t even take this place over…’’ someone said, to general amusement.

Waiting in the gods, there was a peculiar combination of pre-gig ambience (pulsing music, coloured spotlights at the ready, the guy next to me asking: ‘Is this a rock concert?’), and, well, standard middle England, really.

One chap stood – just before Varoufakis finally appeared – to take off his sweater vest; everyone else put down their paperbacks, and picked up their iPhones, poised to tweet the grand entrance.

The show proper was introduced by a happy man from the Guardian: ‘It’s Friday night. We could be out drinking cocktails, but we are here to hear about the economy and Europe. We are hipsters!’ And then, suddenly, there he was.

No leathers or Burberry scarf, but a tight suit jacket over a tight charcoal shirt, a little fist punch, a Churchillian peace sign, and those excellently manicured eyebrows: Varoufakis was in the room, and on the stage.

And so was Paul Mason, who would be ‘in conversation’ with him, since the originally publicised alternative, Pablo Iglesias, would’ve been overkill. Or something like that.

Mason dug straight in, going for what he described as his interviewee’s Mastermind specialist subject: ‘What went wrong in Greece?’

Varoufakis’s answer set the tone for the evening. That is, he explained that almost everything and everybody had gone wrong – apart from him. He had tried to ‘rage against the dying of the light’, yet this hadn’t been possible.

And, thanks to his deep brown eyes and carefree shrugs, this seemed extremely convincing. Except that it was also incomprehensible, confused, and just a bit offensive at times.

Varoufakis has morphed from self-styled ‘erratic Marxist’ economist to lone freedom fighter: his aim in life now being to fight against the ‘democratic deficit’ in Europe. (This, after all, is supposedly what prevented his success in Greece; he is calling for reform based on the live-streaming of political meetings.)

And ‘fight’ is an appropriate word. Varoufakis clearly likes practiced phrases – many of these were violent-sounding (yet coolly enunciated) references to what he was, and is, up against.

The European Central Bank was guilty of ‘fiscal waterboarding’ in a ‘war of attrition’, he claimed; the Greek people had had to choose between ‘an enthusiastic torturer’ and someone who didn’t want to torture them, but needed to. Nice.

Oh, and we must be careful about the ‘working poor’ in Germany: if they become unemployed, they will be a ‘risk for peace’, he said. Twice. Without further explanation – which felt quite uncomfortable.

Maybe it’s relevant that Varoufakis enjoys referencing history (although he said that Corbyn should ‘desist from seeking answers from the past’). Indeed, his responses tended to follow a pattern, something like this:

1) Begin with an impressive – albeit probably uncontextualised – historical example. Ideally, this will relate to the Wall Street Crash, World War Two, or the break-up of the Soviet Union.

2) Throw in some idiosyncratic terminological language. This could be ‘real GDP’, for instance (to explain why Greece ‘wasn’t on the road to recovery’ at the end of 2014).

Or, ‘Why do the pieces of paper you buy have to be mortgages?’ (to explain how quantitative easing would increase productivity and employment, if it were to involve purchasing bonds in green energy).

3) Use catchy metaphors, such as: ‘Do you want milk from this cow that is Greece? It is sick.’ Or, perhaps, compare a ‘shady EU practice’ with a sausage: ‘If you knew what was in it…’

4) Raise those eyebrows, as if to say: ‘Of course, you lot are clever. You get what I’m talking about.’ And then add a cheeky twist.

When asked if he’d like to be the next foreign-born governor of the Bank of England, Varoufakis answered, ‘People don’t have faith in (the) left wing…’ So he’d prefer the opposite: to make progress in Greece, they should choose ‘a British Conservative monetarist. But his brief should be written by us!’

That said, the expected discussion about Greek economic policy was almost entirely usurped by the democracy crusade; the word ‘austerity’ was mentioned only once, I think, and not by Varoufakis. Although, he did say, ‘We are in solidarity with our comrades in Spain.’

The EU, as a whole, was his emphasis: ‘You have a referendum coming up. My message, and the lesson from the Greek crisis, is simple yet rich. Those of us who disdain the democratic deficit in Brussels (…) Those (who are) critical, have a duty to stay in Europe – and fight for it and democratise it.’

‘Until what?’ Mason asked, ‘Forever?’ ‘Forever is a long time!’ Varoufakis answered, smiling charmingly, before returning to 1929.

Often, he was funny. Sniggers and blasé confidence received regular interjections of laughter and warm applause (none so thunderous as that following a slick mention of TTIP). It was all very funny, indeed. Until you recalled what was happening in Greece. Is Varoufakis making the rounds of the punditry circuit there?

Now, ‘I’m trying to cause mischief’, he said, explaining that he was no longer representing Syriza as ‘the window of opportunity we wasted has now shut.’ And, anyway, ‘thousands of people want to talk to me’. He’s well on trend, remember.

Varoufakis is intriguing because he’s part of the story. The happenings in Greece were, as he says, ‘a historic moment’. So, why shouldn’t he be cashing in on it? (Don’t let’s pretend he’s not: around two thousand people were at this event alone.)

After all, he’s the guy who showed off his shiny piano in Paris Match, while the cashpoints outside were blocked. So, why not?

Maybe because he’s claiming to be different. He’s fighting for an integrity and honest transparency that he says Europe badly needs. And perhaps he’s right.

But agreeing over that didn’t seem so important on Friday: it wasn’t simply the audience he was attempting to convince to absolve his past behaviour – it seemed to be himself, too.

The last question from the floor forced him to ask, ‘What more could I have done?’ After a few final jokes and historical observations, the best he managed was that he could have ‘been more vigilant of people on my team who, in the end, betrayed us.’ It felt like a smokescreen.

A show with exciting words, commanding vocal crescendos, and manly hand gestures. A show by an aging rocker who needed to check he still had it, and brag about his ‘big audiences in Germany and Barcelona’.

Whether it’s the halls he’s selling out, or himself, Varoufakis certainly still has something. If it’s what he truly wants, however, is something else altogether.