ATTENTION! THIS CONTENT IS A RUSSIP, SO IT MAY BE TRUE, BUT IT MAY NOT BE TRUE.
The Darkhold is a powerful book that appears in the MCU for the first time in the series WandaVision. It gave Wanda great power, but also influenced her character traits and, blinded by her goal, she wanted to capture and possess the powers of America Chavez in the film Doctor Strange in the multiverse of madness. After the events of this production, we know that Wanda destroyed all the books in the entire multiverse, but this is probably not the end of the story.
From a new rumor, we learn that the real author of the Darkhold book in the MCU is Kang himself, who will debut in Ant-Man and the Wasp: Quantomania. It is uncertain what this means for the Chthon demon, but it is possible that he either never existed or was manipulated by Kang, or Kang copied his original writings from the walls of Mount Wundagor. A source for The Cosmic Circus notes that the symbols in the book are similar to those in the show Curls and in Doctor Strange in the multiverse of madness. Rings are a recurring motif, which in turn can be associated with Ms. Marvel and Shang Chi. So what will be the meaning of Kang writing the book? Perhaps it was one of the tools capable of stopping him, but Wanda unknowingly deprived the heroes of this possibility. At the moment, this information should be treated as a rumor, but if it turns out to be true, some pieces of the puzzle are starting to get red.
By the way, scooper DanielRPK reported that Jonathan Majors filmed his scenes as Kang for Loki Season 2, so there are many indications that Phase 5 of the MCU may finally feature a lot more tie-ins between productions.