Scarlet Witch Wouldn't Just Beat Superman, She'd Kill Him

screenrant.com:

While the strength of Scarlet Witch's magic in the Marvel Universe is well-known, it can reach unimaginable levels in the DC Universe, making Wanda so powerful that not even Superman could stop her.

In the JLA/Avengers crossover series by Kurt Busiek and George Pérez, the Avengers are transported to the DC Universe, where they are given the task of finding six precious items in order to save their universe from destruction by Krona. On the other hand, the Justice League must stop the avengers from collecting the items. In JLA/Avengers #2, Wanda is initially unable to perform her hexes as she needs to adjust to the new dynamics of magic in the DC Universe. However, once she is able to tap into the force, she finds that it makes her «chaos magic» significantly more potent than it is in the Marvel Universe. The magic is so strong that with one hex, Wanda is able to knock down all combatants in the area of operations. Even Superman and Wonder Woman confess to being concerned about Wanda's "dangerously powerful magic."

Related: Scarlet Witch's Marvel/DC Crossover Made The Ultimate Comic Sorceress

While Superman's concerns about Wanda's magic are in the context of how it gives her and the Avengers an advantage in obtaining the six items, he should also be concerned about how it will affect him personally. Indeed, since at least Superman #171 by Jerry Siegel and Curt Swan his susceptibility to magic has been DC canon. In that issue, Mr. Mxyzptlk curses Superman with a spell where every innocent remark he makes comes true. Superman admits to his vulnerability to magic, and the problems it's causing him under Mxyzptlk's curse.

If Superman could not overcome the power of a Mxyzptlk prank, what chance would he have against Wanda's