It's Dormammu's world and we're all just living in it. Ever wonder how Dr. Strange, Namor and the Hulk might have turned out had Dormammu cast their fates? Wow... That would make for such a great story. Wish we'd thought of that one before we worked up this issue's... What? We did? A rewrite? Huh. Glad I thought of that!
It should be noted that many of the characters who appear in this issue are not exactly the Marvel Universe characters from the usual universe. Because Dormammu changed reality, they're warped and twisted versions. However, because it still is 616, they are still credited as their normal versions.