The Mad Titan 
Ah, the Avengers. I knew I would come face to face with you sooner than later. It was only a matter of time. But I know you’re not here to talk. You have come here to stop me. To keep me from balancing the universe. But why? I only seek to bring peace, the same ideal your organization stands for. I am avenging those who suffer from the excess of others. The universe has been filled with evil for far too long. But I am not doing this without purpose. I must do this to protect the universe from the same fate that befell my home planet, Titan.  
It was once a prospering planet, similar to your “Earth”. But fate had different plans. We were soon overrun by our ever-expanding population. I tried to stop the growth; save us. No one listened. So that is why I must exterminate half the universe, or we will all die a horrible, pain death. And it is why I must do it forcefully. The people will not listen until it is too late.  
Stark, you are a smart man. Almost as wise as me. You have experienced this yourself. It took watching a good man be taken away by your weapons to stop your manufacturing. You know what it’s like to be too late. Do you want that to happen again? To be too late?  
And Strange, the Sorcerer Supreme, the all-knowing. You must have watched this exact situation a million times over. You know this only ends one way. Do not make me pry the stone out of chest. Give me what I want. 
You shake your heads, but this fate is inevitable. I am inevitable. 
Overpopulation is an evil we must avoid at all costs, and I will do whatever it takes, even if that means taking down every last one of you. However, there is another way. Give me the Time and Mind Stones, and you can walk away, avoid my wrath. I will give you some time to think. But time is ticking. The universe cannot wait forever.