Once tests on "taking over" Stark's body were complete, DeWitt put his plan into action: complete control of Tony Stark's body!! Unfortunately for DeWitt, Stark's pal Jim Rhodes was able to get Tony into a special suit of armor that had "encephalo-controls" which essentially blocked DeWitt's override and gave back Tony control of his body. But -- Stark had to stay in the armor for this to be so! Very pissed off, DeWitt then released his control over Stark, which caused an incredible "feedback" wave to overwhelm Tony. The pain was so intense that Tony involuntarily activated his armor's jets and began to fly out of control until he was rescued by Rhodes.

Eventually, Stark and Rhodes deduced who was behind the whole plot (the Marrs) and Iron Man flew off to destroy the DeWitt/Marrs lab which was the HQ behind the Stark "takeover." His nervous system nearly shot, Iron Man laid waste to the lab, but then had to deal with Kearson DeWitt in his own set of armor! DeWitt had Stark on the ropes until Jim Rhodes appeared in another set of IM duds to save the day! Together, the two IMs beat DeWitt.

DeWitt was thought to be dead but later appeared in the pseudo-Armor Wars "Assault on Armor City" cross-over (IM Annual #13). It was actually this storyline where his origins were revealed and where he was finally killed (we think).

First ever & IM appearance: Iron Man #258.