SENTINELS

The most dangerous Sentinels ever deployed were not drawn up in Bolivar Trask's laboratory. During Avengers & X-Men: AXIS #1 (2014), by Rick Remender and Adam Kubert, the Red Onslaught — the Red Skull wielding Charles Xavier's stolen telepathy — reached into Tony Stark's sleeping mind and found the files Tony had compiled during the Civil War: detailed plans for defeating every hero he knew, in case his friends ever had to be stopped.

Working through the sleeping Stark, Onslaught turned those contingency plans into hardware: two Stark Sentinels, giant robots built from nearly indestructible adamantium, dressed in Iron Man's own red and gold, and loaded with the weakness files of the Avengers and the X-Men. Their favourite weapon was not a cannon but a Pym-particle ray that shrank heroes down and locked them away inside the Sentinels' own bodies, collecting Earth's defenders like specimens.

The machines captured hero after hero precisely because they had been designed against heroes — and that specialisation was their undoing. Magneto arrived with a rescue party recruited entirely from villains, opponents the Stark Sentinels had never been programmed to counter, and the tide turned. One unit even survived the event to menace the Avengers again in later stories. The bleakest line in Sentinel history may be this: their ultimate model was a good man's homework, stolen out of his head while he slept.