I know the Hellfire TV series was cancelled. To me it is unfortunate because it would be so cool to have a TV show about these characters. Since its cancellation I had been having epiphanies about how a TV series about the Hellfire Club, had it ever happened, would work and how it could be integrated in the X-Men movie world (and possibly TV series like Legion and The Gifted as well).
The plot would have been set in the 1950's, being a sort of prequel to X-Men: First Class and The Gifted. The seasons would pass through time as they show the evolution of the Hellfire Club since its conception until the point when the Club resembles the one we see in First Class. Season 1 would be set in 1950, season 2 would be in 1953, season 3 in 1956 and season 4 in 1959.
The characters season one would be Sebastian Shaw (the main character and founder of the club), Harry Leland (the close friend of Shaw), Shinobi Shaw (Sebastian's young son), Lourdes Chantel (Shaw's wife), Magneto (Shaw's former experiment and enemy), Azazel and Riptide (these last two will be introduced mid-season). The season would also feature Steven Lang, which would be the series version of The Gifted's Jace Turner, and he will be one of the first "government guys" to find out about mutants. Magneto won't have a lasting appearance, only appearing once every three episodes to emphasize his hatred for Shaw, but never fighting the Hellfire Club face to face. Charles Xavier and Mystique could make a cameo in this season. The plot would revolve over Sebastian Shaw's estabilishment to the United States, after the end of WWII, and develops a gambling and drinking site, that becomes the core of his new Hellfire Club.
Season Two would be set three years after. It would feature the Upstarts, a mutant group which would be an antagonist to the Hellfire Club, calling themselves "mutants". The group contains Fabian Cortez as the leader, Siena Blaze and the von Struckers. The von Struckers would later join the Hellfire Club and become recurrent members. A young Otto Strucker could appear. Magneto will passively ally with the Upstarts to take down the Club, but never makes it. A cameo of Ms. Maximoff could appear. Lourdes Chantel could die in the series final, and could also cameo Sabretooth in the final post-credits scene.
Season Three would be set in 1956. Shinobi Shaw would become more angry with his dad and will eventually rebel against him, becoming the leader of the Upstarts. Shaw eventually defeats the Upstarts, which are allied with Creed Financial (which is leaded by Sabretooth, and secretly funds mutant slavery), and abandons his son in a mental hospital. Magneto ends up allying with Steven Lang, which is secretly working for Trask and Stryker (which could cameo) and recently confirmed the existence of mutants and plan the highly anticipated Sentinel Program. Magneto nearly finds and defeats Shaw, but it finds out it was just an illusion, made by Emma Frost, which seems to be working in the shadows with no knowledge of anyone, not even the Hellfire Club. Shaw becomes terrified of all the work he has to do to maintain the Club and resigns his title of leader and hands it over to Mr.Dane, a businessman, and former pilot, which is given the opportunity to control the finances of the Club and lead it.
Season Four is set in 1959. Shaw becomes aware that the Club was having loads of attention, and he joins himself with Leland, Azazel, Riptide and the von Struckers to kick Mr.Dane out of the leadership and hand it over to Shaw again. After Leland and the von Struckers find Erik Lehnsherr, a large fight ensues between them, and Leland is accidentally killed. The von Struckers return and tell Shaw the bad news, as they are introduced to new member, Emma Frost. Shaw ends up promising to kill Erik, but before he can, Shaw becomes emotionally tied to Emma Frost and both fall in love. Shaw expresses his desire to create a helmet that can protect his mind from the telepathic abbilities of Frost, designing it and sending it to a secret Russian scientific division. To locate Erik, Frost secretly infiltrates the CIA and uses the recently-made Cerebro (Beast and Moira Mactaggert could make cameos). When Shaw finds Erik, all the other Hellfire Club members prepare to kill Erik off guard, but Shaw dismisses the idea, as he always loved him as a sort of son. Shaw walks away and prepares his plans to create a homeland for his mutant brothers and sisters. In anyway, the von Struckers approach Magneto and attempt to convince him to join the Club, but Erik admits he never saw them in his life, which confuses the Struckers. The von Struckers find out that Emma Frost brainwashed Erik, and removed his memories of any involvement with Sebastian Shaw, except the death of his mother. Terrified, the von Struckers abandon the Club and make justice with their own hands. In a final post-credits scene, it is revealed that Emma Frost telepathically forced Shaw not to kill Erik and she was the one who comvinced him to make him fall in love for her and she was the one who placed Shaw's idea of world domination (in a cool final twist).