"I believe in the Devil, the possibility that you and I could be having a serious conversation, and suddenly the Devil could walk into the room. The conversation would have to stop." It stops anyway. Robert Lepage, the fêted French-Canadian writer, performer and auteur, cackles, a touch demonically, into the conversational void. We're in the bowels of the Barbican, a dressing-room that is eerily, excessively mirrored, which exaggerates his otherworldly appearance. From the age of six, Lepage has suffered from alopecia. Today his wig is a funky, chestnut, elfin affair, but his lack of eyebrows, eyelashes and preternaturally smooth, hairless chin lend him the compelling aura of a temporary visitant to earth.
As do his pronouncements. A conversation with Lepage is like one of his shows. He leaps from the mundane to the dazzlingly poetic on the most tenuous of segues, and whenever you think you've got his number, he'll satirise himself until you lose it again. "I haven't become a Satanist," he laughs, "but I am fascinated by the character of the Devil."
This is by way of explanation as to why he wanted to direct Stravinsky's 1951 opera, The Rake's Progress, which opens at the Royal Opera House tomorrow. Based on the 18th-century prints by Hogarth, it boasts a magnificent neoclassical score and one of the greatest librettos ever penned, by WH Auden and Chester Kallman. But what drew Lepage to the project was his identification with the character of Tom Rakewell, lured by the temptations of the big city, who marriesa bearded lady and loses his soul and sanity to the Mephistophelian Nick Shadow in an ill-fated hand of cards.
Lepage has dragged Hogarth to Hollywood, setting the opera in the American West Coast of the 1950s. When Tom gambles with the Devil, he goes to Vegas to cut the cards.
In 2004, Lepage spent six months in Sin City creating uber-show Kà for fellow Quebecois cultural megalith Guy Laliberté of Cirque Du Soleil. "Vegas is the city of temptation," Lepage says. "I think perhaps it is an experiment by Nasa. If we're going to send people to Mars, how will we create false economies and cultures to satisfy them? Vegas has the answer. People go there when they've nothing left to lose. There are always two maids working together in the hotels of Vegas, as they find bodies of suicides all the time."
Whenever Lepage comes to town, the whiff of the circus isn't far behind. For three decades his work has drawn either scathing opprobrium or wild adulation. One critic described his solo show The Far Side of the Moon as the greatest event of his theatre-going life when it opened at the National in 2001. Ecstatic audiences agreed. He's famed for making theatre for people who don't like theatre, playfully surreal, marked by a tension between nostalgic romanticism and an ultra-modern technical wizardry, an inimitable visual flair and the ability to link deeply personal stories with improbably vast intellectual themes. Whenever theatre is accused of being a dying art, Lepage is cited as proof otherwise.
Yet, for every groundbreaking work, there is a messy, occasionally muddy, critical debacle. As recently as 2002, his La Casa Azul, about the Mexican artist Frida Kahlo, was dismissed as intellectually tired and emotionally limpid. Today, Lepage claims to have developed an immunity to criticism: "I don't disagree with the critics often, and I'm not destroyed by bad criticism any more. There comes a point when you go beyond it."
Which makes him sound like a dangerously pompous prima donna. But whatever else you might accuse Lepage of – exorbitant spending on his shows, (Kà cost a faintly immoral £87.8m) reducing actors to tears by changing his mind days before an opening, or weeks afterwards, creating solo shows that only he has the charisma to carry – the prima donna appellation refuses to stick. "I thought that with The Andersen Project," he says of his triumphant solo show at the Barbican in 2006, an eclectic ode to Hans Christian Andersen, "that all the headlines would read 'The emperor's new clothes'. It didn't happen. But actually, that is what you have to be careful of: that nobody's noticing when you aren't wearing anything."
Lepage is unpretentious in person. At home in Quebec with his partner of 14 years, the writer/performer Kevin McCoy and their dog Comet, he spends his time "eating and watching television. I'm a good North American." And although turning 50 felt like "a big wall" last December, he took the edge off it by "hanging out with people a few years older than me. It's a good trick. I advise it."
Whatever the media furore surrounding him, Lepage emanates an aura of contained calm. "My boyfriend is a Buddhist who chants twice a day," he says "He tells me I have a Buddha nature. I hope he wasn't referring to my weight. But I believe in the Buddhist idea of flowers blooming from the muddiest waters."
Lepage's past is undoubtedly muddied. His alopecia rendered his childhood painfully isolated, and a terrifying experience with an opium-laced joint at 14 crushed him with agoraphobia for months until his younger sister, Lynda, now his assistant in Quebec, forced him to perform in a school play. He claims the experience saved his sanity and forged an unbreakable bond between him and the theatre.
His home, by contrast, was deeply divided. His parents adopted two children before moving to Quebec and conceiving Lepage. He and his birth sister consequently spoke French, while their elder siblings, having been brought up in Nova Scotia, spoke English. His house, Lepage notes, was a "metaphor for Canada".
That linguistic tension is an experience he will explore at the Barbican in his forthcoming show Lipsynch, a tie-up between his company, Ex Machina, and the small, Northumberland-based Théâtre Sans Frontières. The show, which opens in September, has been six years in the devising, and will run for a buttock-trying nine-hour duration.
Voice, language and speech are the "divine trinity" behind Lipsynch, issuing from the father, the mother and the self – though the father "could be your mother's female lover". "The father's voice belongs to the person with the greatest emotional impact on your mother when you are in the womb," he explains.
Lipsynch promises to relentlessly pursue the idea of how we come to own language, through the repeating arcs of nine characters across seven decades (from 1945 to 2015). Of course, Lepage says, the show is not a departure from his lush visual style, and "yes, some actors will appear in multiple stories, to hold it all together – it's like plaiting a braid". But ask him to divulge that unifying narrative, and he pauses. "It's very complex," he chuckles. "And also, it's not done yet."
For most, such uncertainty would be crippling. For Lepage, it is crucial: "I try to keep two things in my work: doubt and chaos. People ask me: have you a recipe, a 'language Lepagean'? I say no, keep that idea away from me, I don't want it. I like to go out on a limb."
Centre stage: How Lepage has taken theatre by storm
The Dragon's Trilogy, 1985
The then 27-year-old Lepage's five-hour investigation of the connections between East and West launched his international career. Rapturously received for its inventive language and emotional charge
The Seven Streams of the River Ota, 1994
Interwoven tales of post-Hiroshima grief; appalled critics when it opened, as it over-ran by two hours; two years of workshopping later, and it was hailed as "spellbinding"
The Far Side of The Moon, 2000
Lepage played two brothers, one a brash TV weatherman, the other a failed, introspective academic, both in mourning for their mother. Their relationship is likened to that of the US and the Soviet Union in the space race
The Andersen Project, 2005
A satirical lament on loneliness and loss, as a displaced French-Canadian rock star is asked to write an opera based on Andersen's tale The Dryad and arrives in Paris in search of critical affirmation