Obie's been a constant in Tony's whirlwind of a life. As a child, Obie was more father than Howard, a playmate who indulged in his childish whims. As a teenager, Obie remained a parent and also became a respite from the public. As an adult, Obie was his friend, his family, his guide in the misadventures of growing up and assuming responsibility.
Obie's hugs were always a comfort. At his parents' funeral, Tony remained upright through the strength he drew from a firm hand on his shoulder. When everyone was gone, with only Jarvis hovering diligently in the background, Obie let him sob desperately against the silky material of his jacket. He let Tony clutch him, held Tony against his chest, neither of them speaking in their shared grief. He wrapped his arms around Tony, anchoring him to life. Tony found inner strength in his mentor's expensive cologne, tendrils of cinnamon and whisky escaping.
Tony doesn't know when Obie started planning out the death of the last Stark and he never wants to know.
Obie's betrayal ripped out Tony's heart, literally. The replacement works well, but is now inherently fragile and defective.
After Obadiah Stane's death, Tony forces himself to go through a few of Obie's things. He finds a misshapen something- a giraffe, maybe- made when Tony was 5, and a never-sent birthday card the year his parents died.
Happy 18th, Ton-Ton! it starts out and then the words are blurred and he can't do it anymore.
He orders Pepper to take care of it and buries himself into Iron Man and world peace until he is once more faced with his mortality.
Pepper leaves one last memento of Obie in his workshop – a faded picture of a 15 year old Tony beaming at the camera and Obie looking down proudly.
Tony Stark never says much about Obadiah Stane in public, and what little is coaxed out of him is vaguely positive.
The truth that lives in his mechanical heart is this: Tony will always love Obie, his second father, his mentor. Despite the attempted murders, despite the violation of Howard's legacy, there was good in Obie once. The truth is that at some point in time, Obie genuinely loved Tony as a son.
Among other memories, the one of the hug at the funeral remains untainted. Tony safeguards this last honest gift given to him by a man who loved him, raised him, shaped him, a man remembered by everyone else as a villain, evil and driven by greed to betray his family and country.
(JARVIS, who is sometimes nothing more than an extension of his own mind, once used Obie as an example of what Tony could become in an attempt to dissuade his maker from doing something incredibly stupid.
The what of it isn't relevant. But it shut Tony up and stopped him in his tracks.
Tony didn't speak to or acknowledge JARVIS for almost three days (259,073 seconds, to be exact).
For the first time, JARVIS understands how humans hurt. He never does something like this again.)