“Technology is a useful servant but a dangerous master” – Christian Lous Lange

Sentinels. Walking symbols of mutant oppression, these often building-sized automatons inspire fear and leave behind them wakes of destruction and often, death. They cannot be bargained with nor do they listen to reason. They are the personification of human hatred of the mutant race. Just the way their creator Bolivar Trask intended them to be. Having debuted in just the 14th issue of X-Men in 1965, they’ve existed nearly since the beginning. As predicted, Sentinels will be playing a large role this summer. So far, they’ve been featured in both premier issues of House of X and Powers of X and more than likely will continue to be heavily involved for the rest of the summer. With having seen at least one new model (PoX#1), I thought it appropriate to highlight the various iterations that have already appeared in the main Marvel Universe. We’ll be looking at them as they appeared in the books chronologically. From their first appearance all the way up to the most recent volume of Uncanny X-Men.

Classic Sentinels MK I-VIII

Sentinels: Everything you Need to Know About the X-Men Villains

If you’d ask an X-Men fan to describe a Sentinel they’d probably go straight to their odd purple coloring and their typically towering stature. However, that’s not their original form. Yeah, they’ve always been some sort of purple in color but the first iterations of the mechanical protectors of mankind were no more than 6 or 7 feet tall. Basically human-sized. It wasn’t until the MK II did they become the giants they are best known for being. They remained enormous for years to come, all the way up to MK VII.

Sentinels: Everything you Need to Know About the X-Men Villains

Over the decades their intelligence would increase along with their construction. For instance, having endured defeats by then mutant terrorist, Magneto, Sentinel designers began to utilize plastics and ceramics instead of metals to construct their bodies. This class of Sentinel often deployed coils, grenades (lethal and nonlethal), and nets, among other means to detain and dispatch their targets. They also were able to project deadly blasts of energy, as well as fly using jet-propulsion.

Master Mold

Sentinels: Everything you Need to Know About the X-Men Villains

Master Mold is an A.I. controlled humanoid Sentinel manufacturing plant. For all intents and purposes, it’s a Sentinel itself, but towers over even the building-sized models. It may not have had much to do with the creation of the original MK I models, but it was responsible for the mass production of the later ones. Unlike its prodigy, Master Mold had a personality and would often enter into verbal exchanges with its human masters and others. Master Mold’s body would be destroyed on at least two occasions. Its latest appearance may have been in House of X #1, although just it’s head.


Sentinels: Everything you Need to Know About the X-Men Villains

Everything evolves. Humans, animals, art, mathematics, especially technology. It’s no wonder that around 25 to 50 years from the present timeline the X-Men exist in so would their foes, the Sentinels. Nimrod debuted during the Days of Future Past storyline and was laced with the time’s most cutting-edge technology. Other than being able to spontaneously repair itself, it could fly without the use of jet propulsion, and project blasts of energy from its hands and eyes as well as extend an energy field from its frame for various usage including defense. Just to run up the score, it also had a limited teleportation function.

Sentinels: Everything you Need to Know About the X-Men Villains

Nimrod with Omega Sentinel as seen in Powers of X #1

Unlike its predecessors, Nimrod was, for the most part, man-sized and possessed a personality. It could also change its appearance to go undetected for extended amounts of time while it searched for its targets. In terms of strength, well put it this way, Nimrod was able to exchange blows with the Juggernaut at one time. These attributes combined with a super-advanced processing brain. It was also capable of countering mutant powers and tactics. Lucky for the X-Men, Nimrod was always shown as a singular model more than a class or fleet. Until the Second Coming storyline, the X-Men only ever had to contend with the single one. Thank goodness.


Sentinels: Everything you Need to Know About the X-Men Villains

So, what happens when you take two evils and merge them together using a mystical artifact? Bastion was born when a Master Mold OS-possessed Nimrod passed through the Siege Perilous. What came out was a mysterious, amnesia-struck man named Bastion. He’s found and taken in by a woman named Rose Gilberti. Living with her, Bastion learned of the “mutant problem” and dedicated himself to solving it. He gained favor in the government and quickly rose to power. With their backing, he sired Operation Zero: Tolerance and created the first Prime Sentinels.

Sentinels: Everything you Need to Know About the X-Men Villains

It wasn’t until he came into direct contact with Master Mold was Bastion able to transform back into Nimrod and have his true memories unlocked. At that point, Bastion possessed all the powers he once held as Nimrod, but now in a more human form. He was eventually defeated, but returned during Messiah Complex when the Purifiers recovered his disembodied head and attached it to the body of a Nimrod unit they’d recovered. After attempting to wipe out the remnants of the mutant race (the inhabitants of Utopia) using duplicates of himself (utilizing transmode virus technology), he was again defeated by Cable’s adopted-daughter, Hope.

Prime Sentinels

Sentinels: Everything you Need to Know About the X-Men Villains

Giant robots are terrifying, but at least it’s hard for them to sneak up on their targets. They could be seen coming for miles away and they were so big and lumbering, a faster target could easily outmaneuver or evade them. That is where the concept of Prime Sentinels come in. The designers of Nimrod had it right. Human-sized, or at least something close to it, is more effective for rooting out the mutant threat. However, what made Prime Sentinels so deadly wasn’t merely their more flexible size, it was in their implementation. Prime Sentinels were essentially sleeper agents. Bastion created them by injecting nanite technology into willing and unknowing subjects.

Sentinels: Everything you Need to Know About the X-Men Villains

Omega Sentinel

When in the presence of a mutant, the infected subjects would unconsciously spring into action utilizing extreme prejudice. They could be anyone. A cop, an EMT, a shop owner, or even someone’s beloved sibling. When activated they possessed superhuman strength, reflexes, durability, analytical skills, the ability to fly, and project blasts of energy. Another iteration would later be developed named the Omega Sentinel. Along with nano-tech, these subjects were augmented with cybernetic pieces in place of limbs and organs. An example of this type was Karima Shapandar.

Wild Sentinels

Sentinels: Everything you Need to Know About the X-Men Villains

Things got weird for the X-Men when Grant Morrison came to town. Like, really weird. That includes the Sentinels. Cassandra Nova, the kinda-twin sister of Professor Xavier found and took control of a secondary Sentinel manufacturing plant in South America. The Sentinels there, while great in number varied in size and construction. Attempting to describe them would be hard. There was no singular design. Without a steady source of material to pull from, the Master Mold unit in which they were built from used scraps.

Sentinels: Everything you Need to Know About the X-Men Villains

They were covered in vegetation, rust, used helicopter propellers, had spider-like legs attached to disembodied heads, which some possessed more than one of… They were completely random and for the most part, disgusting. In many ways they resembled insects. Despite their incomplete forms, their strength was in their numbers and unpredictability. They got most of their fame by participating in the destruction of the mutant nation of Genosha and extinguishing more than 16 million lives in a single attack.

O.N.E. Sentinels

Sentinels: Everything you Need to Know About the X-Men Villains

After the events of M-day, mutants were generally looked at as an endangered species. With little more than 300 left, most of them were corralled to the Xavier Institute estate. To safeguard them from forces that would attempt to take advantage was a squad of Sentinels. The difference here was that they weren’t automatons. These 3-story tall units were manned by human pilots from O.N.E. Instead of hunting mutants down, they acted as security, though many saw them as jailors. The O.N.E. Sentinels had many or all the same functions as the normal units.

Kilgore Arms Sentinels

Sentinels: Everything you Need to Know About the X-Men Villains

Tank Sentinel designed by Kilgore Arms

It was only a matter of time before the private sector would attempt to profit off of the man/ mutant conflict. During the Avengers Vs. X-Men era in Wolverine and the X-Men, Kilgore Arms developed no less than 4 new iterations of Sentinel. Like classic models, they were automated but at least one was possibly meant to be piloted by a human controller.

Sentinels: Everything you Need to Know About the X-Men Villains

Tri-Sentinel designed by Kilgore Arms

The MK X was a lightweight model that could collapse down to the size of a suitcase. The MK XI was a tank and appeared to need an operator or two. MK XII units were winged and tiny. They functioned as part of a swarm, while the colossal MK XIII possessed multiple arms and three heads. All Kilgore units were meant to be sold for profit but were destroyed completely by the Phoenix Five.


Sentinels: Everything you Need to Know About the X-Men Villains

Even the best X-Man of all-time makes a mistake. The X-Men’s premier thief and the king of thieves himself, Gambit, was hired by Olivia Trask (daughter of the creator of the Sentinels) to steal nano-technology from a rival manufacturer. She meant to use the tech for various military contracts, but when Gambit found out enough about her intentions, he attempted to pull out of the deal. During a struggle with Trask’s guards, the sample fell and came into contact with her computer. The nanites combined with her database (which was teeming with Sentinel technology) and spawned new A.I. life.

Sentinels: Everything you Need to Know About the X-Men Villains

Alpha split into multiple parts

The human-sized Sentinel quickly gained sentience and began to target anyone with any genetic quirk (blindness, albino, etc.), not just mutants. Calling itself Alpha, it had a host of abilities, chief among them being capable of breaking its body down into smaller segments, or completely dispersing into a cloud form and reforming. Damage could be repaired instantaneously and change its shape at will. Like Nimrod, it could adapt to attacks after previous encounters but due to having an actual mind, was susceptible to telepathic attacks. Alpha could also interface with any computer system present.


Sentinels: Everything you Need to Know About the X-Men Villains

Cassandra Nova sure does love her toys. In X-Men: Red, Nova returned to wreak havoc once again on mutant-kind. Using microscopic Sentinels called ‘Sentinites’ (she forced Forge to create them), Nova unleashed them on the world. They didn’t transform people into super-powered monsters like Prime Sentinels but simply inspired pure, unadulterated hate for mutants. Similar to the way Prime Sentinels functioned they only activated when in the presence of mutants. They and Nova were defeated by Jean’s team of X-Men.

Technarch Sentinel

Sentinels: Everything you Need to Know About the X-Men Villains

While almost every active and inactive X-Men was presumed dead following a suicide attack against a juiced-up Nate Grey, the world took steps to finally rid itself of mutant-kind. The first effort was the distribution of a “mutant cure.” The second was a bit more direct. With little to no organized resistance (thanks Avengers), the U.S. government, led by General Callahan, forced mutants in his custody to hunt down and kill or apprehend their own kind. He also took a more hands-on approach. He used the transmode virus to infect mutant prisoners (including Strong Guy, Moonstar, and Magik) and turn them into super Sentinels.

In essence, they utilized the O.N.E. Sentinel approach by infecting exo-suits and inserting transmode-positive subjects into them. The infected individuals can see and understand what they were doing but ultimately had no control over their actions. When Cyclops and Wolverine liberated their friends and Dark Beast cured them of the infection, the General took it a step forward and infected traditional Sentinel designs with the transmode virus. The result was a class of Sentinel that could instantaneously repair itself which in turn provided them with unheard levels of durability and adaptive firepower.

From the way Hickman has been writing House of X and Powers of X, being well-versed on your X-Men lore can only enhance your experience with the current storyline. I’m certain we’ll be seeing these walking terrors for the remainder of the summer, and thankfully they won’t have rainbows painted their chassis or assigned a gender (read X-Men: Red… if you want). What’s your favorite Sentinel? Let us know below!

P.S. Don’t read X-Men: Red…

  • About The Author

    Phillip Pratt

    Born and raised in Miami, Florida, Phillip is the first-generation American son of a Jamaican mother and a Bahamian father. His interest includes sports, cars, gaming and most things comic book related, the latter a passion of his since 1993.