New IM scribe Joe Quesada takes a cool idea only touched on previously in Iron Man's history -- namely, an armor that comes to life. We had seen an LMD (Life Model Decoy) of Tony Stark become self-aware way back in volume 1 #17-18, and then we witnessed a version of the IM armor gain awareness in the first-ever computer-generated graphic novel CRASH.

Now, the new IM armor comes to life through a combination of factors: the downloading of the Jocasta computer program (vol. 3 #20), a lightning bolt precipitated by the new Whiplash, and most incredibly, a Y2K computer glitch! (Seriously!) At first the Sentient Armor wishes to become "one" with Tony Stark, but after brutally beating then killing Whiplash with Tony Stark inside his shell, the Sentient Suit gets angry at Tony for his unwillingness to "join" him. Soon, the Sentient Suit causes Stark's girlfriend Rumiko to leave him, and generally wreaks havoc on Tony's life in general. Eventually, Stark confronts his rogue armor in his older Modular Armor, which the Sentient Suit trashes easily!

The Sentient Suit puts Tony inside his shell and deposits him on a deserted island where he gives him a choice: become "one" with him....or die. As the Sentient Armor is about to kill Stark, he suddenly receives an Avengers Priority call signal! He jets off to answer the call, believing there is nothing Stark can possibly do to prevent death upon his return. This belief proves fatal, as Tony frees himself and proceeds to set a series of traps for the armor. When the armor returns to the island, Stark actually succeeds in harming his rogue suit, but cannot stop it. As it appears that the Sentient Suit is about to apply the death blow to Tony, it suddenly plunges its fist into its own chest -- and yanks out his cybernetic heart! The heart attaches itself to Tony (as he was again prone to a weak heart) and the Sentient Armor passes away, "realizing" a part of humanity after all -- sacrifice.

In later issues (specifically IM vol. 3 #48), it was revealed that it was actually the "Ultron Imperative" -- programmed into former robotic bride Jocasta -- that formed the consciousness of the Sentient Armor. The evil Ultron's programming conflicted at times with that of the kinder, gentler Ultron 12, hence the vacillating between "moods" of the suit.

First IM Appearance: Iron Man vol. 3 #26.