The X-Men have had to fight against the likes of many evils in their near sixty-year history. They have fought against the prejudices of mankind who fears them, and they have fought to protect mankind from the threat of powerful mutants who believe they are the true dominant species. No matter what form the evil took, these villains have always offered up a glimpse of what happens when one group tries to enact control over the other. One of the most deadly and recognizable repercussions of this constant war resulted in the creation of the Sentinels. These are the five most dangerous Sentinels ever created 

Master Mold 

There’s a very simple reason why Master Mold makes this list: He’s essentially the father of all Sentinels. When Bolivar Trask first created the Sentinels, he needed a way to mass produce them. Enter Master Mold, a super-computer in the form of a gargantuan Sentinel. Master Mold’s sole purpose was to facilitate construction of all the Sentinels. He also acted as a hive mind for all the others. Unfortunately for Trask, Master Mold decided that the best way to protect humanity was to enslave it. 

Prime Sentinels 

The Prime Sentinels differ from their fully robotic brothers in that they were actually humans who were implanted with advanced cybernetic nanotech via the program, Operation: Zero Tolerance. These Sentinels were used as sleeper agents. Once activated by their creator, they transformed into powerful armored cyborgs with advanced weapon systems. Their ability to hide in plain sight made them a far greater danger than the normal Sentinel variety. 

Omega Sentinel 

Karima Shapandar was a police officer in India before being transformed into a Prime Sentinel during Operation: Zero Tolerance. Shapandar was much like her brothers and sisters in the program in that she had no knowledge of her abilities until she was activated. While helping a mutant named Neal Shaara to find his brother, Neal’s mutant power triggered Shapandar’s transformation into an Omega Prime Sentinel. 

Nimrod 

In the alternate timeline “Days of Future Past,” Sentinels control most of North America. The advanced prototype Nimrod is the descendant of the original Sentinels. Nimrod is virtually indestructible, with the ability to shapeshift and repair himself. He is essentially the most perfect form of Sentinel. Nimrod is so powerful; he is even capable of engaging the Juggernaut in combat. He is also responsible for killing Katherine Pryde in this timeline. 

Bastion 

The creator of the Prime Sentinels is also the combination of the essence of two of the most powerful sentinels ever created: Master Mold & Nimrod. Previously believing himself to have been born human, Bastion was actually created after Master Mold absorbed Nimrod into its own systems. The X-Men were forced to banish Master Mold into a pan-dimensional portal called the Siege Perilous. From there, he was reborn. Bastion assembled the anti-mutant strike force Operation: Zero Tolerance, which created the Prime Sentinels.