Because Hecate was the Goddess of Magic, she is the greatest sorcerer of all the Olympians, second only to Zeus. Her skill in magic is so great that she was capable of warping reality around the entirety of Brooklyn and its inhabitants single handedly without any artifacts required.
Scarlet Witch's power is the strongest sort of magic in the MCU, much as it is in the comics. Wanda's ability to use it to rewrite reality, not to mention Agatha's reaction when she realised what she was up against, says volumes about its potential.
One Above All is the creator God of the Marvel Multiverse and is the single most powerful character in the Marvel Universe. This mysterious supreme being hasn't appeared in any of the MCU movies so far but captivated many Marvel Comic fans. One Above All is an omnipotent being and his weapon is love.
Wanda and Doom travelled to the Other-Realm, empowered by the true Darkhold, to defeat Chthon. Wanda backstabbed Doom and took the true Darkhold for herself. She fused with the true Darkhold which granted her the power to defeat Chthon and absorb the Elder God entirely.
Wanda was considered to be the Nexus Being of Earth-616, but there were still forces far more powerful than her. Perhaps the most obvious character that was more powerful than the Scarlet Witch was the One Above All, who acted as the "god" of the Marvel universe.
Of the Avengers who can beat Scarlet Witch, Vision is one of the strongest contenders. With an Android created using the Mind Stone, Vision possesses a vast array of abilities that could potentially match Scarlet Witch's reality-warping powers.
Her name is Neena Thurman and she's the luckiest mutant in the entire Marvel Universe. Literally. Aside from being a skilled mercenary, Neena's mutation is that she's lucky almost all of the time.
Hela is the Asgardian goddess of death, inspired by the Norse goddess Hel. In the comic books, the Asgardian king Odin (Thor's dad) appoints her to rule over Hel, a dark underworld-like hell, and Nifleheim, a sort of icy purgatory.
Hela, the Asgardian Goddess of Death, rules two of the nine realms: Hel, land of the dead, and Niffleheim, land of eternal ice.
Zeus Was the First of the Official "Gods" in the MCU.
While most of the Avengers can easily be turned into monsters, Hulk seems to avoid this fate simply by refusing to listen to the magic.
Wanda Maximoff Is the Most Powerful MCU Character
Wanda Maximoff suffered a similar fate. Her Avengers: Age of Ultron introduction gave her mind control, flight, and the ability to shoot generic energy beams from her hands.
The massive cosmic force of nature appears to be completely immune to magic. Galactus is -- both literally and figuratively -- a huge part of the Marvel Cosmic Universe. He's a cosmic constant, an essential part of the cycle of death and rebirth in the universe, helping to maintain necessary balance and order.
Amatsu-Mikaboshi, the Chaos King, is a fictional character appearing in American comic books published by Marvel Comics. The character is usually depicted as a supervillain and demonic god of evil who is best known as an enemy of Hercules and Thor.
The Sentry was the most powerful member of the New Avengers. He was also the unluckiest. The Sentry was his own worst enemy, with the dark aspects of his personality coming to life as the Void.
After all the destruction the Scarlet Witch caused, Earth-838's Wanda ends her tirade with a single line; "Know that they'll be loved."
Scarlet Witch is indeed powerful and has overpowered magical abilities that make her a threat in both the comics and the MCU. But the thing is that Dark Phoenix is a threat to the entire universe as her powers are cosmic-level. In that regard, it is easy to see why Dark Phoenix is the more powerful character.
However, Black Bolt would likely have annihilated Wanda with a single word. It's evident that the Darkhold-corrupted Scarlet Witch is incredibly powerful as a prophesied wielder of chaos magic.