This article contains spoilers for Doctor Strange in the Multiverse of Magic.
Doctor Strange in the Multiverse of Madness destroyed both the Darkhold and the Book of Vishanti, changing magic in the MCU forever. The MCU has tied its version of magic to the multiverse from the beginning, with the Ancient One telling Doctor Strange sorcerers draw power from other universes and use it to shape reality itself. It was, therefore, always inevitable that Stephen Strange would be the first MCU superhero to plunge into a multiverse of madness.
There is a sense in which Doctor Strange 2 was a story of two books - specifically, two books of magic. Scarlet Witch had come into possession of the Darkhold, a forbidden book of dark magic apparently created by the first demon, Chthon. Doctor Strange believed another book of magic could be used to counter the Darkhold, the Book of Vishanti, which he pursued into the multiverse - only for it to be destroyed before his eyes. Strange was left no choice but to use another version of the Darkhold itself against Scarlet Witch, drawing on the blackest of magics and risking his soul to save the multiverse.
Both the Darkhold and the Book of Vishanti are lifted straight from the comics, but in the MCU both now appear to be gone. This will undoubtedly have a profound effect on the MCU's multiverse, as Doctor Strange attempts to deal with the repercussions of this crisis. It may even set up an even greater crisis than Scarlet Witch's multiversal rampage.
The Darkhold In The MCU & Marvel Comics Explained
In the comics, the Darkhold was created by Chthon, one of the Elder Gods who ruled Earth in prehistoric times. Although some of these Elder Gods were good, others burned with a lust for power, and they learned they could absorb the power of their kin by consuming them. So began a dark war that threatened to destroy the Earth itself, one that saw the most predatory and malevolent Elder Gods become some of the most dangerous beings of all time - Chthon among them. Chthon foresaw a time when Scarlet Witch with Chaos Magic, his own power.
The MCU's version of the Darkhold was introduced in WandaVision, with the witch Agatha Harkness apparently coming into possession of it some time ago. She revealed there is an entire chapter of the Darkhold dedicated to the Scarlet Witch, and Wanda Maximoff took it to learn the secrets of Chaos Magic. Unfortunately, just as in the comics, to read the Darkhold is to be corrupted; its magic reduced Wanda to her deepest, darkest emotions of grief and jealousy, essentially transforming her into a monstrous version of herself. It took a glimpse of the humanity that should have been hers to shake Scarlet Witch free of the Darkhold's baleful influence.
Why The Book Of Vishanti Is So Important In Doctor Strange 2
Doctor Strange in the Multiverse of Madness introduced the spells from the Darkhold to defeat Scarlet Witch.
Are The Darkhold & The Book Of Vishanti Actually Destroyed?
Both the Darkhold and the Book of Vishanti were destroyed by Chthon's Chaos Magic, while the Book of Vishanti is a conduit for the light magic of the three Vishanti. Those conduits may be gone, but the beings who created them are not.
Doctor Strange's use of the Darkhold resulted in his being granted a third eye on his forehead. In the comics, this is traditionally seen as a blessing from Agamotto himself, granted only to the purest of heart. But it's notable that the evil Doctor Strange possessed the same third eye, and Earth-616's variant only gained it after using the Darkhold; in the MCU, it could well be a manifestation of Chthon rather than Agamotto, a last foothold in the multiverse now the Darkhold has been destroyed. Either way, it is clear the powers behind the Darkhold and the Book of Vishanti are still out there, and Doctor Strange's story will intersect with theirs.
MCU's Magic Future Without The Darkhold & Book Of Vishanti
The destruction of the Darkhold and the Book of Vishanti changes the balance of magical power in the MCU. On its most basic level, it means the taint of the Elder God Chthon's magic has been largely removed from the multiverse. The magic contained within the Darkhold will be lost forever, and it's even possible no other variant of Wanda Maximoff can ever become the Scarlet Witch, because the Darkhold's magic appeared to be bound in some strange way to her transformation in WandaVision. It's more difficult to figure out the significance of the loss of the Book of the Vishanti, because there was only one copy in the entire multiverse, meaning its spells were likely known to few.
It's possible Scarlet Witch made a mistake when she destroyed the Darkhold. According to Doctor Strange 2, beings from one universe must be careful not to leave too significant a "footprint" in another, lest they cause an interdimensional collision known as an incursion. Wanda Maximoff has destroyed every universe's version of the Darkhold, the ultimate source of dark magic - which means she could have destabilized the multiverse, setting up the MCU's version of the "Secret Wars" event. The Darkhold claimed Scarlet Witch was destined to destroy all things, and Scarlet Witch could have unwittingly fulfilled that prophecy in Doctor Strange in the Multiverse of Madness when she destroyed the Darkhold itself.
