Rather than read Marvel comics to prepare for the role of Agent Mobius, Owen Wilson instead had Tom Hiddleston explain the entire Marvel Cinematic Universe to him.
In the comics, each agent of the Time Variance Authority resembled Marvel Comics writer/editor Mark Gruenwald. This was a joke as Gruenwald's job as editor was to maintain continuity across the Marvel Universe.
It's well known that Marvel is strict about spoilers getting out. Owen Wilson revealed he 'let it slip' that he grew a mustache for his character, Mobius. He said later that day, he received an ominous text from an unknown number saying "Strike 1". He said it might have been Kevin Feige using a burner phone and made sure he was careful when talking about Loki.
The TV series is intended to have a major impact on the Marvel Cinematic Universe, serving as a link to Doctor Strange in the Multiverse of Madness (2022) and Ant-Man and the Wasp: Quantumania (2023).
Ke Huy Quan said of his casting as OB, "Now you have to understand, when I became an actor again, joining the MCU was at the top of my wishlist. I was so excited and I said, 'Could this be it?' I was driving. I picked up the phone. And on the other end I hear, 'Hi Ke. This is Kevin Feige.' He went on to talk about how much he loved [Everything Everywhere All at Once (2022)] and how much he loved my performance. Then finally he says, 'Ke we would love for you to join the MCU family.' I was driving at that time. I start tearing up, and I couldn't see the road anymore. I said, 'Kevin, can you give me two seconds?' I pulled the car over, put it in park and I said, 'Please continue.' He says, 'We have this great character for you, Ouroboros. I really love him, and I think you will be perfect to play him.' He told me about Loki. He told me about the MCU. He spoke [with] so much passion and enthusiasm in his voice. It brought me back to the day when I met him for the very first time on the X-Men (2000) set when he was just an associate producer, and I was an assistant action choreographer... He loves this universe so much. He has such a vast knowledge of this universe. And little did I know only 23 years later, I get to work with him. I get to play a wonderful character."