‘I’m bored!’ declares my companion while yet another naked body is hoisted – like Jesus – onto a makeshift cross. ‘‘This is shit!’ he shouts above the discordant organ and brass band.

Workers dressed in white pour blood into the mouths of the nude man and woman. They are blindfolded. The liquid bubbles around their expectant lips and spills down their chests, creating a sticky red river. It gathers around their genitals and – drip, drip, drip – collects in a pool on the canvas floor.

We are a third of the way through a three and a half hour performance by Hermann Nitsch that can only be described as a marathon of the dark arts. The Austrian artist is in Hobart to direct his 150th Orgien Mysterien Theater (Theatre of Orgies and Mysteries), otherwise known as ‘actions’, for MONA’s Dark Mofo festival. A sacrificial ritual involving 500 litres of blood, a bull carcass, and – later – lots of lithe bodies squirming in entrails, it is graphic and explicit, a ceremony that requires complete surrender to the senses.

With some 1,000 people loitering around the cold, cavernous warehouse, however, it feels like we, the audience, are being tested as much as the strung-up savants. Nearing 80 years old, Nitsch overlooks his bloody theatre like a macabre Santa Claus: rotund, with flowing silver hair and beard, he presides over a table where offal is displayed like glinting jewels on an altar.

As ‘disciples’ are stretched naked – at one point, a woman is turned upside down on a cross, legs pressed together as crimson blood is poured into her crotch, creating the illusion of grotesque menstrual flow – only the slightest flicker of emotion crosses his forehead. It reminds me of the Red Wedding, the infamous massacre scene in Game of Thrones, and Nitsch feels eerily omnipresent, a puppeteer silently egging on his charges to cross ever more into the obscene.

Dark Mofo’s decision to put on 150.Action, of course, attracted the ire of animal rights activists: more than 22,000 people signed a petition demanding that the performance be stopped (festival organisers received death threats). On the day itself just a few dozen protestors stand outside holding up placards and hand-held mirrors – ‘to make you look at yourself,’ one tells me.

Nitsch, too, calls himself an animal rights activist (the bull used for the performance was already destined for the slaughterhouse and killed at an abattoir prior to the event.) If nothing else his actions are a reminder of what eating meat really means in a sanitised supermarket world. MONA founder David Walsh, a vegetarian who watched the entire performance wearing a shirt covered in kitsch neon grapefruits and clutching a plastic cup of red wine, stated in April: ‘I want the audience to ponder why meat for food is okay (at least people aren’t protesting at Mona’s barbeque), but meat for ritual or entertainment isn’t.’

Nitsch is part of a group of Viennese artists known as The Actionists whose post-war, visceral, violent performance art demanded that the audience confront life at its most brutal: so controversial were the works that he was arrested in Austria three times. Half a century later, his pieces remain confronting and the so-called ‘relics’ – canvasses containing stains from the event or, more poetically, paintings with blood – are reminders of the carnage he carefully orchestrates.

Saturating the room is the stench of raw flesh. More overwhelming still is the repetition. True, there is a build up of tension (one man’s privates are covered in animal organs; when he is carried out he shakes uncontrollably). Still, for many, the question is less if such performances count as art and more if they remain interesting.

‘I won’t be going to see Nitsch because I think that as an idea and as a spectacle, his animal sacrifices and bloody entrails performances have been done to death… Deadly boring. Spare me; spare the bull. The moment when such a work was avant-garde is long… dead,’ wrote Maria Kunda, a lecturer in art theory at the University of Tasmania, in April. Or as one friend put it the night before, ‘Forget the cow! What about me?’

Then, two hours in, something shifted. What was painful, dull, frustrating, becomes suddenly thrilling. Or, more uncomfortable still, moving.

A slight naked girl is lain down in front of Nitsch on the floor, blindfolded, a female sacrifice to a potent male force. Behind her, wheeled out on a giant trolley, is, finally, the bull. As the music pumps up, its shroud is ripped off and the carcass is hoisted – headless, skinned, legs splayed – from a wooden pulley onto a chariot and paraded through the crowd. Finishing its cavalcade, it is disembowelled: disciples dive inside its guts in a frenzied, feverish dance. Standing beside me, Walsh’s wife, American artist Kirsha Kaechele, whispered: ‘It’s beautiful.’

And it was. Beautiful and disturbing. Not just because of the paganistic and religious overtones (the elaborate drinking of blood seems to channel drinking the blood of Christ) but because of the restraint and officiousness of the process, too.

Directing the floor was Nitsch’s second-in-command, a graying man in white with a whistle around his neck, glasses perched on his nose, and a clipboard under his arm. As the bloodbath unfolds around him, he refers to his schedule, slotting leaves into a folder. Reminiscent of the Nazis, who committed genocide with the tightest of paperwork, or the Aztecs, who went through elaborate rituals to kill children to appease the gods, the hysteria was less chilling to me than whistle and clipboard.

By the end, half the audience remained. In a crescendo operatic in scale, the bull is opened up entirely and the performers dive in, mixing fleshy tissue with oranges and grapes, a celebration of both death and fertility. The music heightens and Nitsch – until now, seated – stands up, eyes lifted to the heavens, and raises his hands to implore the disciples to go further, further still. I look over to my companion. He’s now in the midst of it all, cheering wildly, standing in offal, his face ecstatic. There is blood on his shoes.