Imagine being the last of your kind: a powerful warrior and sorcerer. Thanos wants you to fight on his side and so offers you whatever your heart desires. But you made your heart up long ago, and it did not involve him.
His expression softened when his eyes rested on you. If he had an ounce of belief, he would call you a legend, a god. The only survivor of the universe's oldest and most bloodthirsty kind. It was no secret to anyone that your favor would most definitely shift the power struggle. Both sides, Thanos and Avengers, have heard of you bringing entire civilizations to their knees, making the most prideful emperors cower in fear and begging for their lives, all while you did not even bat an eyelash. A merciless soul occupied your devilish body, although some might argue about the former. Chaos found a home in you.