After spending half the interview discussing his penchant for wickedness, it should be noted that Iwan Rheon may be one of the nicest people in the industry. Neither of his two signature roles – awkward misfit Simon and maniacal bastard Ramsay, nor his latest incarnation as the villainous Maximus on Marvel's Inhumans – are visible in the cheerful, chatty young man who prepares for the photoshoot by rolling a cigarette with a couple of the production team.

Iwan Rheon

Obviously, an actor and his characters are separate entities, but the disconnect is still startling: it’s very hard to relate the Rheon of the flesh with the Rheon of the screen. Which is testimony to both his talent and his charm. (The accent helps. It still carries a heavy trace of his native Wales; and even the worst obscenity is softened by the Welsh accent.)

For the photoshoot we commandeer Peckham knifemakers Blenheim Forge. Rheon displays admirable fortitude standing in front of two glowing furnaces for the better part of an hour. Even from a distance the heat is noticeable. At least the weather keeps everyone cool: it’s early August, after all.

Anyway, Rheon is used to colder – he filmed Game of Thrones in Northern Ireland, which substituted for the perpetually frozen North. He laughs when I ask whether Ramsay’s death in season six prompted a slew of similarly psychotic characters being thrust his way.

“I did get asked to do a few, yeah. That’s how it works. It’s easier for producers to cast someone that they know can already do it than for them to try something new.”

Even if you’ve never watched an episode, you’ll know Game of Thrones. You can’t not know Game of Thrones and be a sentient human in the year 2017. However, if you don’t know Ramsay – in a show crammed with bad eggs, young Master Bolton stank worse than anyone else. He murdered more or else every character he came into contact with (including his father and infant brother), raped his wife on their wedding night, and never missed an opportunity to feed people to his dogs. (Animal lover, though: nobody is irredeemable.)

Which is funny, as Rheon was very nearly cast as brooding protagonist Jon Snow: the heroic inverse of Ramsay. His main rival for Jon, Kit Harington, was a friend of a friend. Harington got the part, but Rheon made enough of an impression to be offered the Ramsay gig.

Reflecting on the process, Rheon is phlegmatic. “It was kind of weird being up against someone that you know, but that’s the game, man, that’s how it is. If you don’t get the role you can’t be bitter about it, that’s how it goes. Sometimes it goes your way, sometimes it doesn’t. As a fan, watching the show, I think they probably made the right choice.”

Would Harington have been a good Ramsay?

“No,” says Rheon fondly. “He’s very earnest, which is one of his greatest qualities. What he’s brought to Jon Snow is amazing, and every season he grows and grows.”

Rheon nominates Jon as his preferred occupant of the Iron Throne. “I think he’s the best. But everyone’s gone a bit mad

So Harington played Jon, and Rheon got to have “tremendous fun” portraying the vilest specimen in the Seven Kingdoms. Yet as well as becoming the ‘vile specimen’ go-to guy for producers worldwide, Rheon picked up some additional baggage from his stint on Thrones.

“That fucking GiF of that sausage, man!” he laughs. “That will haunt me forever!”

Ah yes, the sausage. After Ramsay castrated the unfortunate Theon Greyjoy (Alfie Allen), he celebrated by chowing down on a large pork sausage in front of his utterly traumatised victim. The scene spawned numerous memes and GiFs of Rheon playfully waggling the surrogate member. Rheon has lived with this ever since.

“I inadvertently ordered a jumbo sausage while buying chips with Alfie once. I genuinely just wanted a jumbo sausage. He just looked at me, and was like “are you fucking serious?”

I’ll let you into a secret: square mile considered photographing Rheon slicing a sausage but the actor politely – if firmly – declined this concept. “No sausages. No way.”

Iwan Rheon

As it happened, the sausages had been left at the office – which would have been something of a blessing if we hadn’t already dispatched someone to collect them. About five minutes after Rheon made his anti-sausage stance known, our courier cheerfully hove into view carrying a plastic container. The container was quickly thrust into a bag, and its contents consumed the following day.

Despite the irritation of the sausage legacy, Rheon can see the flipside. “I guess again it’s a testament to the show, how big it is and how much people really care about it.”

Unfortunate GiFs aside, Rheon can now enjoy the rest of Thrones as a fan, knowing as little as everyone else. He nominates Jon as his preferred occupant of the Iron Throne. “I think he’s the best. But everyone’s gone a bit mad – Bran’s gone mad! Arya’s gone a bit too.”

Maybe there’s some truth in the theory that the undead White Walkers will ultimately prove to be the heroes of the whole thing? Rheon laughs, and slips into an impression of a mournful snowman. “Ooh, why is everyone so mean to us? We’re so lovely!We just want to cuddle! We just like ice.”

I’m not normally one for writing love songs, but it just felt right

Although he earns his coin as an actor, Rheon’s great love is music: Dinard, his debut album, was released in 2015. A rather beautiful collection of acoustic guitar tracks, Dinard attracted warm reviews and proved far from the typical actorly vanity project. (We’re too polite to offer contrasting examples.)

The album is named after the Brittany village where Rheon met his current girlfriend. Is that the most romantic thing he’s ever done?

He chuckles. “Yeah, probably. Yeah. The title track is kind of about the night that we met, and the feeling of it. I’m not normally one for writing love songs, but it just felt right and I thought that should be the title of the record.”

The romantic night in question involved a spot of skinny dipping…

“Yeah! It was a pretty rock’n’roll night.”

Must have been cold?

“Exceptionally cold. It was October.”

I suggest that he’s a brave man, and he erupts into a fit of giggles.

“Yeah! I was hoping she could see past that.”

Iwan Rheon

He hopes to release a second album, but acting will always be the day job. “That means the music then doesn’t become my career and about money.” He views it as a hobby, a creative release unshackled from any director or script.

Rheon may keep acting and music separate, but what did he think of the much-maligned Ed Sheeran cameo in Game Of Thrones?

“For me, it took me out of it,” he says, echoing the opinion of every viewer. “They could have done it in a way where it wasn’t so obviously him or something… By really featuring him it distracted me from the show, and it annoyed me a little bit because of that. I was so excited to see this new season, and then it’s like, ‘what’s he doing here, they don’t need to do that’. I don’t know why they did.”

Rheon has spent much of his career being asked his preferred form of superpower. (Teleportation, if you're wondering.) He made his name as a juvenile delinquent granted invisibility in the bawdy E4 cult classic Misfits. That was back in 2009, but with a major role in Marvel’s latest TV project, Inhumans, the superpower stuff has resurfaced again.

“After all these years I've gone back to that,” says Rheon. He chuckles. “It's quite funny how those things happen – but in something completely different.”

It’s certainly a graduation of sorts. Inhumans trades in the type of comic-book lore which Misfits so joyously subverted. The series centres on the Inhuman Royal Family, a group of superpowered beings who live on the moon. Although they rule over a peaceful society, it is far from perfect – a rigid caste system bestows higher social status on those with the strongest powers.

Iwan Rheon

Although Rheon had never heard of Inhumans, the audience is certainly there. “When you speak to the fans of Marvel comics and stuff, you immediately see that it's a story that everyone's been waiting for, and I'm surprised it's never been done before.’

Rheon is Maximus, powerless apart from his formidable intellect and rhetoric (which count for little), but brother of the king (which counts for rather a lot). Although his royal blood affords Maximus a life of luxury, his literal humanity remains a handicap – especially considering his kingly brother, Black Bolt, has a voice so powerful even a whisper can cause untold destruction. Black Bolt is rubbish at dinner parties.

“He's looked down and belittled all the time,” Rheon says of Maximus’s lack of powers. “Bullied for it basically.”

Inevitably, Maximus triggers a coup against his family, and the Inhumans escape to Hawaii – well, if you must be exiled somewhere… Anyone wishing to know more will have to watch the show.

His career might be bookended by superheroes, but Rheon attained global fame in another form of fantasy, playing the malignant Ramsay Bolton in the cultural phenomenon that is Game of Thrones. A dream role, for sure, but one that spawned a difficult question – how do you follow playing the most hated character of the biggest TV show on Earth?

Obviously everyone says, 'oh, you're just playing another villain.' That's something I have to battle with.

Rheon knows comparisons between Ramsay and Maximus are inevitable; he nearly turned down the Marvel role due to his reluctance to return to villainy. The fact Maximus bears the sobriquet ‘the Mad’ in the comics hardly suggested a departure from the psychotic Ramsay.

“I pretty much almost said no,” Rheon admits. “Because I felt that it was just going to do the same thing again that I'd already done.”

Inhumans showrunners Scott Bucks and Jeph Loeb gave their assurances that the TV Maximus would be a complex creation, and a new challenge. Rather than cackling sadist, Maximus is a flawed politician convinced in the rightness of his cause. His desire to abolish the caste system should win plenty of viewer sympathy.

“That's what Marvel do really well: it's not as plain who's the baddie and who's the goodie. It's not quite like that. Hopefully people will maybe be torn and say, 'you know, actually this guy is saying some pretty sensible things.’

“[Maximus] always felt that he'd make a better King, and he probably would. He'd have made a great leader.”

The distance between Ramsay and Maximus is neatly encapsulated by Rheon’s inspirations for the two characters. Ramsay famously channelled a combination of Heath Ledger’s Joker, Dennis the Menace and Liam Gallagher “for the walk”. To prepare for Maximus, specifically his oratory prowess, Rheon studied the speeches of John F Kennedy.

Iwan Rheon

“It was a very interesting thing for me to watch. When you listen to Kennedy's speeches, he's a wonderful speaker, and he's got that real passion – you feel like he's almost singing it.”

He even copied JFK’s hand gestures while speaking. “I nicked his hand thing!” He grins. “I did do that, yeah.”

Anyone expecting to see a reprisal of Ramsay Bolton will be in for a shock.

“It's a very different role,” says Rheon, “although obviously everyone says, 'oh, you're just playing another villain.' That's something I have to battle with. That's my personal battle.”

Our conversation returns to superheroes, and the brilliant, anarchic Misfits. Rheon’s Simon began the show as a reclusive oddball before transforming into the dashing ‘Superhoodie’ in season two. I watched Misfits in university, and I remember the episode in which Simon revealed himself as ‘Superhoodie’ prompted a sudden lusting after Rheon among my female housemates.

Did he notice a sudden spike in attention after the episode was aired?

“Um… yeah, maybe a bit,” he concedes cautiously. “There was certainly a huge shift in the perception. It was kind of weird actually. It did happen exactly like that. It was very strange.”

I’d love to do Othello. I’d love to play Iago

For several years a Misfits film seemed likely, yet never quite took off.

“There was a script,” said Rheon. “I read it and at one stage it was happening. I don’t know what happened, I think it was to do with financing, and it fell through. I don’t know if it’d work now – I think we’re too old. I don’t think anyone wants to watch us all now, in our 30s.

“Unless they came up with a new concept it would be difficult. I would have loved to have done it, but I don’t think it’ll happen now.”

So no film, but there is an American version in the works. Has Rheon met its Simon?

“I don’t know the actor’s name, I’ve seen a picture of him. I’d love to see it.”

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Both Skins and The Inbetweeners were remade across the pond, and neither captured the charm of the originals. Can such an inherently British show as Misfits work there?

“That’s the challenge, man. I don’t know.”

What’s the American equivalent of – “Thamesmead?” Rheon laughs. “I don’t know!"

Happily, locating the transatlantic Thamesmead isn’t Rheon’s problem. He has Inhumans to concentrate on – and after that?

“I’d like to go back and do some stage acting. It’s been a long time. I’d love to do some Shakespeare because I’ve never done that.”

I ask which play; the answer comes quickly: “I’d love to do Othello. I’d love to play Iago.”

It’s hard to think of a role this most amiable of psychopaths would be better suited to. Iago says to Othello, “I am not what I am.” There is certainly more to Rheon than meets the eye.

Marvel’s Inhumans is out on Sky 1 this autumn.