"You." Thanos said with a smirk as he spotted Tony, raising a brow in disbelief as his senses began picking up on the subtle differences. "A second version of The Iron Avenger. Fascinating. You will send a message to Peter Quill. You will tell him that Thanos is coming for him. And that this time, I will not stop until he and his band of misfits are annihilated."
He used a combination of his telekinesis and matter manipulation to focus... and temporarily shut down all the operating systems in Tony's armor, making him essentially trapped in a big piece of metal.
"And when you see my daughter, Gamora... send her my love." He said with sarcasm and venom dripping from every word, before telekinetically pushing the now motionless armor back toward Knowhere.