The two sisters seemed to have started a grievance session.
Gamora said Thanos had slaughtered her homeland and killed every last member of her family.
Nebula said Thanos had turned her into a cyborg and used her as a tool, cold and devoid of all emotion.
They did everything they could to prove that it was impossible for them to feel something like love for Thanos.
Because they were suddenly afraid.
Afraid that what Leon had said was true.
Just moments ago, they really had hesitated at the thought of personally throwing Thanos off the cliff.
They refused to believe they could deeply love Thanos, their nominal father but actual enemy, executioner, and demon.
"You can argue all you want, but the facts will not change."
"Most Parallel Worlds are like this. You can see for yourselves."
Leon had no intention of wasting words trying to persuade them.
A red glint flashed through his pitch-black eyes.
Gamora and Nebula stopped arguing at once.
Their gazes instantly became hollow, as though they had turned into puppets.
Yet their consciousness remained clear.
From each of their perspectives.
They suddenly woke up in their usual beds.
Vormir, Superman, all of it had vanished.
The two rose in confusion, and before they could understand what was happening, each of them received Thanos's orders.
They could only begin racing through one star system after another without pause.
And began living another completely different life.
Searching for the Cosmic Orb, encountering Star-Lord, forming the Guardians of the Galaxy, resisting Ronan, seeing through Ego, Infinity War...
Leon used an illusion to let Gamora and Nebula each experience a life from their respective Parallel Worlds.
From Guardians of the Galaxy 1 all the way to Avengers: Endgame.
The last thing Gamora saw was Thanos tearfully throwing her off