Jonathan Hickman is set to take the X-Men in a bold new direction with the announcement that he will be launching new X-titles following the upcoming House of X and Powers of X events. While this means the current line of X-titles will be canceled before the event, it's an exciting rebranding of the franchise that hopes "to return the X-Men to their rightful prominent position in the Marvel Universe."
The X-Men's history is full of many dangerous villains that have threatened mutantkind over the years, but none have haunted the X-Men as long as the mutant-hunting robots known as the Sentinels. Today we'll take a closer look at the different types of Sentinels that have appeared in the comics to see who is the most dangerous threat to mutantkind.
10 MARKS I-VII
The classic Sentinels were created by Bolivar Trask and first appeared in X-Men #14 from Stan Lee and Jack Kirby. The various Sentinels were created by the main production unit known as Master Mold, who would go on to cause many problems for the X-Men over the years.
The Sentinels were towering robots that could detect the mutant gene in order to capture or kill mutants and were equipped with various projectile or energy weapons and able to fly. New models featured different weapons and upgrades, such as being able to adapt and counteract any superpower the Sentinels came across.
9 SENTINEL SQUAD O*N*E
The Mark VIII model of the Sentinels was created by Stark Enterprises following the decimation of mutants at the hands of Scarlet Witch in House of M in an effort to provide security for the remaining mutants while also keeping a watch over the tense X-Men teams.
The main difference between this version is that it required a human pilot to operate, which led to the formation of the Sentinel Squad O*N*E, led by James Rhodes/War Machine. While the idea for Sentinel Squad O*N*E was inspired (albeit fairly insensitive), it ultimately failed and the Mk VIII Sentinels were destroyed.
8 PRIME SENTINELS
The Prime Sentinels debuted during the "Operation: Zero Tolerance" event that ran through all the X-titles in 1997. Led by Bastion (more on him later), a government agency began capturing mutants and attacking known targets like the X-Men with cybernetic nanotech-enhanced humans who had been unknowingly transformed into Prime Sentinels.
While Primes may have lacked the size and firepower of their predecessors, their covert nature as human sleeper agents allowed them a new level of stealth and infiltration. Not all Prime Sentinels blindly followed Bastion, as Karima Shapandar/Omega Sentinel had her mind restored and even worked alongside the X-Men.
7 BIO-SENTINELS
One of the more grotesque versions of the Sentinels was also incredibly dangerous for a number of reasons. First introduced in Warren Ellis and Phil Jimenez' Astonishing X-Men #31, the Bio-Sentinel first appeared in the form of deceased mutant Laurie Collins/Wallflower before transforming into an organic Sentinel and attacking the X-Men.
The Bio-Sentinels were being made from dead mutants and came equipped with Brood clones that shot like missiles from their fingertips, increasing their danger level immensely. This idea was revisited more recently in the latest volume of Uncanny X-Men that revealed Sentinels and mutants had been bonded together using the alien Transmode virus.
6 TRI-SENTINEL
Surprisingly enough, the Asgardian Loki was actually responsible for the creation of the Tri-Sentinel. Following the failure of his Acts of Vengeance plan, Loki fused together three prototype Sentinels to create the Tri-Sentinel who was tasked to destroy a nuclear reactor. Tri-Sentinel was stopped by Spider-Man, who had been empowered with the cosmic energy of Captain Universe.
The Tri-Sentinel appeared recently in the pages of Nick Spencer and Ryan Ottley's Amazing Spider-Man, and at one point was even piloted by Spider-Man to become Spider-Bot. Spider-Bot then fought against an army of duplicate Tri-Sentinels, though they were all ultimately destroyed.
5 NANO-SENTINELS
The Nano-Sentinels were microscopic machines created by Cassandra Nova, Charles Xavier's evil psychic twin (more on her later). They first appeared in Grant Morrison's run on New X-Men and were part of a larger attack on the X-Men by Cassandra and the Shi'ar Imperial Guard, who she had manipulated into conflict with the X-Men.
The Nano-Sentinels had been making the X-Men feel ill with unknown symptoms, weakening the team prior to the attack. It was only with the intervention of Xorn that they were able to burn out the nano-Sentinel infection. Nova refined her technology more recently into Sentinites, which attach to humans brains, giving them the ability to detect mutants and forcing them to incite panic and attack mutantkind after detection.
4 STARK SENTINELS
The Stark Sentinels first appeared during the AXIS event, and as the name implies, were created by Tony Stark using all of the information on superheroes he had gathered after the Civil War event. Stark was under the influence of the Red Skull, who had evolved into Red Onslaught after surgically gaining powers from Professor Xavier's brain.
The Stark Sentinels had an adamantium coating, specialized weapons systems designed to combat the various heroes of the Marvel Universe, and used Pym Particles to shrink their targets down to imprison them inside the Sentinels. It was only the intervention of Magneto and his team of supervillains that turned the tide and stopped the Stark Sentinels.
3 NIMROD
The highly advanced Sentinel unit known as Nimrod hails from a possible future and was sent back in time to stop an event that could change its home timeline. After completing its mission, Nimrod stayed in the present day and set about eliminating the X-Men, following through with its programming to eliminate all mutants.
Nimrod was able to shapeshift and rapidly repair itself and was eventually bonded with Master Mold by the mystical Siege Perilous to become the previously mentioned villain Bastion. There have been a few different iterations of Nimrod over the years, but each version represents the eventual pinnacle of Sentinel technology, making it one of the most dangerous Sentinels around.
2 WILD SENTINELS
Cassandra Nova would appear frequently since her creation by Morrison during New X-Men, with a singular goal of destroying all mutants, the complete antithesis of her psychic twin Xavier's goal for human/mutant harmony. In one of her most devastating attacks on mutantkind, Nova managed to eradicate millions of mutants using Wild Sentinels.
Wild Sentinels were created by a secret by Master Mold from a U.S. government-funded operation to create self-sustaining Sentinels that could evolve themselves using any nearby resources. Nova took control of the Master Mold unit and created Mega-Sentinels that attacked the mutant island of Genosha in a horrible act of genocide that left mutantkind close to extinction.
1 OMEGA SENTINELS
While the Omega Sentinels don't differ greatly from the other classic models in appearance, they continue to haunt the X-Men after their appearance in the iconic "Days of Future Past" storyline by Chris Claremont and John Byrne. "Days of Future Past" would be revisited many times and also served as the inspiration for 2014's X-Men: Days of Future Past film.
The storyline partially took place in a possible future where the Sentinels had taken over North America and hunted down and killed or imprisoned almost every mutant in internment camps. This storyline highlights the X-Men's greatest fear that the mutant-hunting robots designed specifically to kill them would ultimately fulfill their purpose.