Shinobi Shaw

Shinobi Shaw, also known as a Black King of the Hellfire Club, is a fictional supervillain appearing in American comic books published by Marvel Comics. The character is usually depicted as an adversary of the X-Men and their affiliated teams. Created by Chris Claremont, Jim Lee and Whilce Portacio, the character first appeared in "X-Factor" No. 67 (June 1991). He is the son of the former Black King Sebastian Shaw, and is a mutant with the ability to control the density of his own body.
Fictional character biography.
Shinobi is the son of Sebastian Shaw, the leader of the Hellfire Club. In his first appearance, Shaw is revealed to have engaged in a series of financial machinations to ruin his father, and after bankrupting him, he attempts to kill his father by using his powers to induce a heart attack in Sebastian, and then blowing up Sebastian's home. Shaw is able to briefly take control of the Hellfire Club, assuming the mantle of Black King. Eager to return the Inner Circle to its former glory, Shaw approaches Elizabeth Braddock and Warren Worthington, attempting to convince them to become a part of the Inner Circle. Both X-Men refuse, however. He also tried to enlist Storm under Candra's orders as a member, but she also refused. In his early years, Shinobi often surrounded himself with scantily-clad men and women.
Shaw was a member of the Upstarts, a group made up of Siena Blaze, Graydon Creed, Fabian Cortez, Trevor Fitzroy and probationary members Andreas and Andrea Strucker (of Fenris). They were manipulated by the Gamemaster and originally Selene, but the group quickly turns against her. The group participates in an elaborate game, wherein they hunt and kill assigned targets for points. During one of these games, the Upstarts target the surviving members of the New Mutants and the Hellions, but are defeated by the combined forces of X-Force and the New Warriors. 
After he learned that his father was alive, Shinobi presumably in fear of retaliation for his assassination attempt, deserted all of his inherited positions and returned to a more secretive mode of life, allowing Sebastian to take control of the Hellfire Club. Shinobi then worked with Spiral and Mindmeld as they experiment on Karma's siblings. However, his personal assassin Clear-Cut betrays him and aids X-Force in defeating him.
As a result of the Scarlet Witch's actions, nearly all of the mutants in the entire world were stripped of their powers. Shinobi is confirmed as being one of a handful of mutants who retained their powers following the 2005 "Decimation" storyline. 
When Selene attempted to rise to goddesshood, it was revealed that Shinobi was at some point found and killed by his father, as he was resurrected by Selene with the techno-organic virus and sent with Harry Leland to kill his father and Donald Pierce. Selene was ultimately defeated and Shinobi's fate was left uncertain, as it was unknown if he was among the mutants teleported to Genosha by Blink to serve as a sacrifice to Selene or if he was among those that managed to escape Utopia. 
Shinobi is later revealed to be alive and assembled the Upstarts again to kill the Nasty Boys, in order to lure the X-Men out. The Upstarts are quickly neutralized and after discovering the X-Men were unknowingly working for Emma Frost, Shinobi used his own mutant powers to commit suicide by phasing his hand through his head before muttering that Emma Frost will not get him.
In the 2019 relaunch of the X-Men comics, Shinobi was resurrected on Krakoa by The Five and placed under the care of his father, who appointed him the Black Bishop of the Hellfire Trading Company. Shinobi was unaware of the circumstances of his death, and his father told him that Emma Frost and Kate Pryde conspired to kill him.
After Kate Pride is killed and Shaw's betrayal is revealed through Lockheed, Emma immediately calls Callisto to go after Shinobi, who was having a meeting with Christian Frost. With Cal as her bodyguard, Emma reads Shinobi's mind and finds out that he was unaware of his father's intentions. Emma later makes a dig at Sebastian by questioning his parentage to Shinobi.
Powers and abilities.
Shinobi Shaw is a mutant who can alter his body's density from diamond-hard to intangible. He usually uses it as a means of escape, but he can also use the intangibility to reach into an opponent's heart and induce a heart attack, without any adverse effects on Shaw himself.
Other versions.
Shinobi Shaw appeared in the "Ultimate X-Men" title, as Emma Frost's boyfriend. He is a member of the Academy of Tomorrow, in addition to the Hellfire Club. One of his operatives, Gerald Levine, is currently spying on the Xavier Institute and Marvel Girl, under his orders. When visiting the school, Shinobi and Gerald attacked Jean in an attempt to capture the Phoenix God. This failed, as the Phoenix fought back, and both Shinobi & Gerald were taken into police custody. Later, it is revealed that Emma's also a member of the Hellfire Club in secret.
Later in the "", Tony Stark and Jarvis are seen leaving a party for Shaw in Tokyo to respond to an emergency by Nick Fury.