On the one hand, that's good. That means he wasn't going mad (again), that he really did see something there and really did see that shadow before he revived. But on the other hand, that's bad. What the hell was that thing? And why did Strange feel like he could spot it out of the corner of his eye every now and then?

As Rocket mentions the mark, Strange nods, making a small noise of agreement. After all, something like that happened to his animas as well. "It was the same with Bell. Hers was a blood red marking. I tried to trim it out, but it keeps growing back that same color."