Megatron is briefly alarmed by the infrared and ultraviolet readings coming from the stranger, whose species he does not know. It probably helps a little that he does make an effort to smile and appear a little less threatening. He's used to people being scared of him, although he wouldn't know who Thanos was.

"Interesting. The anti-violence field explains a lot about what Soundwave and Ravage are doing here. I approve of it. I was once an extremely violent person, but I would rather not ever hurt another living thing, if I could avoid it."

He steps into the formally appointed room. "It's beautiful," he says, and nods. "Thank you for your welcome."

Megatron is actually more comfortable now. He's used to having relative strangers address him with fear, lust, or some combination of both--but that behaviour isn't logical, and rarely leads to any sort of worthwhile, lasting tie. Admiration sometimes is, but where there is admiration, there are expectations, and hero-worship can turn into bitter hatred in an astrosecond.

That Loki is apparently trying to assess him somehow makes sense. It shows that Loki is no fool.

Ravage and Soundwave will need more friends like this. And Megatron could use a few more himself.