Sebastian Shaw has been a thorn in the side of the X-Men since his debut during the Dark Phoenix Saga. He's worked actively and behind the scenes. He's viewed his allies as disposable and fought off attempts to dethrone him. That is, until his illegitimate son Shinobi did so with an attack and a bomb.
Shinobi filled his father's shoes quite well at first, but his enemies were very powerful and even included his supposed friends. He was young and impetuous, but very powerful. His resurrection on Krakoa and his alliance with his father is a harbinger of some very tough times.
10 Shinobi: Tried To Recruit Archangel and Psylocke Into The Inner Circle
Early into his ascent, Shinobi Shaw tried to recreate the Inner Circle of the Hellfire Club. The Worthington and Braddock families had long been members of the club. He lured Archangel and Psylocke to the club and made the offer to join him.
When they refused, he attacked with his mutant powers. He initially incapacitated Psylocke, but when she recovered, her assistance humbled Shaw. The X-Men left Shaw alone in the Inner Circle meeting room humiliated.
9 Sebastian: Seized Control Of The Hellfire Club
When Sebastian Shaw, an up and coming member of the Hellfire Club, learned that the White King of its Inner Circle was supporting Stephen Lang's Project: Armageddon and its Sentinels, he was dismayed. When one of those robots killed his beloved, he was incensed.
He had Emma Frost make the White King kill his allies, and then Shaw broke the man's neck and assumed control of the club. He proceeded to use it to forward some of the most diabolical ambitions among mutantkind.
8 Shinobi: Betrayed Selene
With the Upstarts, Shaw received assistance from the HellfireClub's Black Queen Selene. She formed the hunting group to forge the next generation of mutant leaders. They quickly turned on her. She found herself being tortured by Trevor Fitzroy in an attempt to gain leadership of the group.
While Fitzroy did the deed, discussion among the group shows that Shinobi and Fitzroy were strong allies within the Upstarts. Selene's betrayal was necessary for their plans to continue unencumbered. The young villains were about being in charge and under the guidance of Selene was a place that could not abide.
7 Sebastian: Organized The Corruption Of Jean Grey
There was a grand plan the Inner Circle had under Shaw to create a mutant army. First, they tried to beat the X-Men to recruit new mutants, then they captured the X-Men themselves to take their genetic material. Part of this plot included corrupting and recruiting Jean Grey to become the Hellfire Club's new Black Queen.
What followed was Mastermind committing the telepathic equivalent of sexual assault. Inadvertently, it also awoke the Dark Phoenix persona inside the X-Man. Shaw and his contemporaries underestimated the power at Jean Grey's command, paying a heavy price for it.
6 Shinobi: Pit The X-Men Against Emma Frost Before Killing Himself
In the days before the Dawn of X, The majority of the X-Men were believed to be dead. Emma Frost was working to stop an anti-mutant vaccine while Wolverine and Cyclops formed a team to take out mutant threats. One of these threats were the Upstarts, who stopped Emma's agents.
When the X-Men defeated the Upstarts, Shinobi Shaw was the last one, cornered and alone. Rather than be captured and find himself at Emma's mercy he made a cryptic remark that sent the heroes to confront Emma Frost before killing himself by phasing his hand into his brain.
5 Sebastian: Manufactured Mutant-Hunting Sentinels
After being thwarted by the X-Men the first time, Shaw was revealed to be working with the government and manufacturing a new generation of Sentinels. This essentially put him playing both sides of the mutant-human conflict for his benefit. His version was one of the least effective, although still very formidable.
The primary purpose was to escalate the tensions between mutants and humans. The idea was that the Hellfire Club could draw in more mutants to their influence. Essentially, it was an extension of their first plan, which had been thwarted by their sadistic corruption of Phoenix.
4 Shinobi: Helped to Organize The Mutant-Killing Upstarts
As the Upstarts began making their presence known, their cooperation was essential as the X-Men and related teams started fighting back. Shinobi's corporate empire made a lot of this organization possible. He allied himself with one of the group's most effective members, Trevor Fitzroy.
As the group failed, Shinobi retreated from prominence. Mostly this was because he discovered that his father was still alive. His fear of Sebastian Shaw was well-founded since the elder Shaw killed Shinobi off-panel.
3 Sebastian: Convinced Shinobi That Emma Frost And Kate Pryde Murdered Him
When Shinobi was resurrected on Krakoa, it was at the request of Sebastian Shaw. Part of Shaw's plan to seize control of the Hellfire Trading Company involved placing Shinobi as the Red King. When Emma Frost made Kate Pryde Red Queen instead, his plans modified.
Shinobi was resurrected without knowledge of how he had died literally at his hand. When he asked his father how he died, Shaw told him that Kate Pryde and Emma Frost conspired to murder him. This puts Shinobi's desire for revenge in line with Shaw's motives.
2 Shinobi: Murdered His Father And Took Over The Hellfire Club.
Sebastian Shaw found himself locked out of his own company. Enraged, he lashed out at his assistants when Shinobi walked in, claiming responsibility for taking the company away from his father. When Shaw attacked his son, Shinobi revealed his mutant powers had emerged.
SHinobi stuck his hand in Sebastian Shaw's chest and taunted him as a bomb he had planted destroyed the elder Shaw's mountain home. Increasing his density, Shinobi survived.
1 Sebastian: Murdered Kate Pryde
While Krakoa could have been a new start for every mutant, Sebastian Shaw has escalated his schemes to gather wealth and power. He had planned to put his son Shinobi on the quiet counsel as the Red King. Unfortunately, Emma Frost made her power play by putting Kate Pryde, Captain of the Marauders in his place instead.
Shaw set forth a plan to eliminate Kate Pryde by murdering her, guessing that her inability to be recognized by the island would prevent her resurrection. As she sank to her drowning, he explained his plan to gain more wealth through black market selling of the Krakoan drugs to the wealthy. He also plans to replace Emma Frost on the Quiet Council as well. His excruciating murder of Kate Pryde is utterly despicable in its cruelty.