Jack, in Lost, was supposed to die in the pilot episode, but the show runners were impressed enough by the actor’s performance that they made him a lead character.
This isn’t a perfect fit for the OP, but the original script for Pretty Woman was much darker and grittier than the ‘urban fairytale’ it turned into, with Michelle Pfieffer and Al Pacino originally considered to play the leads.
So it was more the characters changing the actors than the actors changing the characters. But it definitely would have had a different tone with Pfieffer and Pacino.
Over the course of M-A-S-H*, Gary Burghoff changed the character of “Radar" O’Reilly from a worldly, somewhat sneaky character who is fond of practical jokes and stealing the CO’s liquor to a naive, innocent teetotaler who sleeps with his teddy bear.
*Which apparently in Discourse is impossible to properly include the asterisks between the letters, because it interprets them as formatting marks.
Or like Frankie and Johnny, which starred Pfeiffer and Pacino, was also directed by Garry Marshall, and came out the year after Pretty Woman. I’m guessing since Marshall decided they weren’t quite right for his Disneyfied version of (originally titled) $3000, which became Pretty Woman, he decided to use them in a grittier production more suited to their talents.
Also on Lost, the character Ben Linus was supposed to only appear in a few episodes. Michael Emerson was so good as the bad guy that they expanded the role into the signature villain of the series. Which led to him being nominated for four Emmys, winning one.
The run-up to the storyline that lead to Favreau being kicked off IM3 as director. He wanted Tony to become an alcoholic like the “Demon in a Bottle” storyline from L&M, and RDJ fought hard against re-living his personal addiction struggles on screen. Looping back around to the thread topic, that might be the significant change he brought to the character. Even with the character’s PTSD, he never turned to substance abuse.
Not trying to be a jerk, but “PTSD” was the only acronym/initialism I recognized in your whole post. The rest is gibberish. IM3? L&M? RDJ? Admittedly, showbiz is not my area of interest or expertise.
This is reminiscent of specialty message boards I read sometimes. A constant stream of abbreviations and acronyms that completely obscures the meaning to anyone not familiar with the topic.
We’ve certainly had threads and threads on whether / how to use initialisms / acronyms in a reader-friendly way here on our general interest board. And in my own areas of expertise, initialisms / acronyms are rampant and it takes real effort to write without them. Effort I usually, but not always, make successfully.
It was funny in an uncomfortable way to read that post which was as Greek to me as I suppose some of mine have been to others. Payback’s a bitch I guess, or at least discomfiting.
I used RDJ to describe the actor in my previous post, I name Layton and Michilinie in same, and I don’t think it’s a crazy leap to deduce what IM3 means after naming the director of Iron Man 1 and 2, Favreau.