Once upon a time—not long ago at all—Nebula would have been miserly with the information. Knowing how helpless most beings would be to make any use of it, even were they capable or willing to believe or understand it.
She still didn't have much faith that anyone could sufficiently assist her. But what she knew for certain now was that she was not enough.
So, spearing straight through any potential smalltalk, she fixed Stark with her mismatched (one organic, one cybernetic) eyes. She didn't know how much he'd gotten before her arrival, so she went with: everything.
"Titan is the planet is he was born on. Its ecosystem collapsed and all life went extinct, from sentient overpopulation. Thanos called it a natural imbalance. He became obsessed with the balance of the universe and convinced that the way to preserve or restore it was by wiping out half of all life. To prevent more fates as on Titan. He went through the universe conquering races and slaughtering half the population at random. Because randomness was the only way to have fairness.
"He adopted an orphan from every race he conquered and made us killers. Corvus Glaive, Ebony Maw, Cull Obsidian, Proxima Midnight, Gamora, and me. As children, he would have Gamora and me battle one another in training. Every time my sister prevailed, my father would replace a piece of me with machinery, claiming he wanted me to be her equal. He pulled my eye from my head and my brain from my skull and my arm from my body because she always won. I hated her for it. For years. I never... until recently… realized… that she was only a child trying to survive, too. That she didn't know it was because of her… didn't see."
A moment's silence… some organic part of Nebula choking her up. She was back to herself and continuing before Tony could respond.
"At some point, my father decided conquering and slaughtering planet by planet, race by race, was too little, too slow, and became obsessed with the Infinity Stones. He deployed his children to search for and collect them. With all six he would be able to wipe out half the population of the entire universe with a snap of his fingers. And think he was the savior of life by doing it. He is a true believer in the rightness of what he is doing. And does it all out of proclaimed Love. Even when he is murdering and torturing. He is more dangerous than anyone ever imagines. ...Even me. I went to hunt my father like a dog. I wanted to tear him apart slowly, piece by piece, until he knew some semblance of the profound and unceasing pain I know every single day. He literally took me apart, and strung me up, telescoped out like a loosened puppet. He used me to get to Gamora before he murdered her for the Soul Stone.
"I don't remember all of what happened on Titan. Except that not everyone appreciated how easily he could defeat us. So he defeated us."
That she'd said parts of the speech exactly like that before was nothing to how often she'd whispered it through her mind. Sometimes it was all that got her to sleep.
Not the bit about it not being I'll-also-kill Gamora's fault. That was… very, very new.
Abruptly, Nebula turned on her heel, away from Tony, and to the coffeemaker. She took the whole urn, took a direct swig, made a terrible face, then proceeded to drain it in a single go.
She set it back down, wiped her mouth with the back of her hand, and returned her gaze to Tony.