Stephen stopped and stared at the blade, followed by the slightest of sighs. The respectful distance wasn't because he was afraid of being attacked, but wary of weapons swinging when there were other people in the vicinity. As it was, he was prepared to put them both in a mirror dimension, just as much as he had been when meeting with Gamora in Grand Central Station. He always had a firm belief as a doctor to do no harm. He held fast to that.
He didn't make a move, not even to raise his hands in surrender or a show of meaning no harm. The cape was smart enough to play at being a cape, and made no move either.
"I'm doctor Stephen Strange," he explained, in such a way that he might as well be serving tea and cookies, "and I'm tasked with protecting this planet from large scale threats. I've talked with Thor a few times now. He's here. I'm also the reason why you've arrived on Earth, or Midgard, although it wasn't anything intentional. The timeline is compromised, and it has brought you here for...well? Honestly, we don't know yet."
Someone was walking by, looking over their attire and drawn weapons.
"Comic con," explained Stephen, when the passerby was close enough to hear.
"Friggin' geeks," was the person's reply as they shook their head at them both, walking away.
Stephen was awkwardly silent, other than the popping of his lips on the p of an otherwise silent 'Yep.'