10 Movie Origin Stories We Almost Got
2. Young Thanos Watches Titan Be Destroyed - Avengers: Infinity War
Despite Thanos (Josh Brolin) being described as the protagonist of Avengers: Infinity War, it's surprising how little we actually learn about his backstory by the end of the Infinity Saga.
However, Joe Russo did confirm that writers Christopher Markus and Stephen McFeely did write drafts of the Infinity War script which featured the Mad Titan's origins:
"We even had a draft where you saw ten minutes of his backstory. You saw him as a child, you saw him try to convince his planet that it was doomed and recommend that they randomly kill half the population to save the planet. He gets sent to a prison off-planet and eventually watches the planet destroy itself. It is a whole other film, but sometimes that's the value in a story room, of writing that draft in the script because you go 'alright, at least I have that in my brain now.'"
Though Infinity War does make it clear that Thanos had to watch as Titan was ravaged by over-population despite his calls for a cull, it would've been incredible to see this play out for ourselves with a younger Thanos in tow.