Can Magneto stop Mjolnir?
CAN MAGNETO LIFT THOR'S HAMMER? Yes,magneto can control magnetic fields not metals. So Marvel had revealed that Magneto can lift Thor's hammer.
It isn't an Earth metal, so Magneto cannot control it to the extent that he can control Earth metals, but he can manipulate it by controlling the surroundings of the hammer and lift it using the Electromagnetism, so I think controlling is way different than lifting it.
Unlike adamantum, Magneto cannot manipulate vibranium – not if it's pure. Vibranium is a rare, extraterrestrial metallic ore. It has near-mystical properties that allow for energy manipulation and more. There is a Wakandan isotope and an Antarctic isotope, and both of them are completely unaffected by Magneto's powers.
Yes, in the comics magneto has been able to manipulate Mjolnir which is made of Uru.
However, Magneto's powers have come up against Captain America's shield in the past, and he has been able to affect the shield via his magnetic powers. He can push or pull the shield magnetically but has never successfully damaged the shield in any way.
Magneto's power might seem obvious, but, for anyone who doesn't know, he has the ability to manipulate magnetic fields. Exerting control over ferrous and nonferrous metal is just a small aspect of what he does. His power extends into the atomic level, allowing him to alter the chemical structures of matter.
We know that Magneto can manipulate adamantium at will: not only can he freeze Wolverine in his tracks with a thought, the comics also saw him rip the metal off Logan's skeleton molecule by molecule.
For unexplained reasons, Thor remains the only one able to lift the hammer in this universe despite Odin never shown enchanting it with the "worthy" spell. Mjolnir returns in Thor: Love and Thunder (2022) with Jane Foster wielding a reconstructed version of the hammer.
In the Ultimate universe, Magneto gets a hold of the hammer by manipulating the electromagnetic field around the hammer, thus using it but not technically wielding/holding it, circumventing any need to be worthy.
Meanwhile, Rogue was also spending a great deal of time with Magneto. She was initially only keeping her promise to the Scarlet Witch, but Rogue's feelings began to grow stronger. Eventually, Magneto discovered that their similar magnetic powers cancelled each other out, which allowed them to touch.
Can Magneto lift colossus?
Magneto can control any substance of Metal. From Adamantium to Uru Metal to the Electromagnetic Spectrum. So yes he can control Colossus' skin.
Capabilities. Telepathic Resistance/Immunity: The helmet protects its wearer from all but the strongest or most unexpected of telepathic attacks. This is achieved due to technology wired into the helmet itself.

While Magneto has gotten his licks in on Iceman, he's never been able to beat the mutant. Even if they were to clash one-on-one, it's still doubtful he'd be able to do so because Iceman is just too powerful.
The nearly fleshless Wolverine jumps up and stabs his claws into Magneto's chest, mortally wounding him. Magneto rips the Adamantium from Wolverine's bones, killing Wolverine, leaving just a severely charred skeleton and an arm of flesh due to his healing factor not working.
Magneto is arguably one of the most powerful (and coolest) of the X-Men. Manipulating the electromagnetic spectrum, he can shift, shape, and summon metal. He's apparently so powerful in X-2: X-Men United that he can use his mutant abilities to rip the iron right out of your blood.
The repulsion can be so great that it counteracts gravity, levitating the object. Because Magneto can manipulate magnetic fields, he can use diamagnetism to levitate himself and others.
Is the Infinity Gauntlet able to be manipulated by Magneto's powers? No.
While vibranium is the more durable material, adamantium is the more dense material. This means that given the right circumstances, adamantium can potentially cut through pure vibranium.
During Avengers: Age of Ultron, Steve Rogers was able to nudge Thor's hammer when others had been unable to move it whatsoever.
Hela Was Worthy Enough to Destroy Mjolnir
Many people other than Thor have wielded Mjolnir, including his sister Hela. But the impactful scene in Thor: Ragnarok depicts Hela catching Mjolnir in mid-air before then crushing it to pieces. Odin previously told Thor the power of the Uru metal had no equal.
Who can control Mjolnir?
No living being may wield it unless they are worthy. This is reflected in the inscription on the side of Mjolnir, which states: Whosoever holds this hammer, if he be worthy, shall possess the power of Thor. For almost the entirety of Marvel continuity, this has exclusively been Thor.
3 Doctor Doom Is Too Selfish To Lift Mjolnir
He's saved the universe on several occasions, but his grudge with Reed Richards and his ego have always stood in the way of him becoming a true hero. These same factors would prevent Doctor Doom from wielding Mjolnir.
Yes, even Spider-Man has been worthy of holding the hammer of Thor.
While it is true that the hammer would have been an incredible asset for the player, it cannot be wielded or even picked up by Kratos (nor Atreus) for several reasons.
The God of Thunder has finally proven himself worthy to wield Mjolnir, and he throws it straight at Hela, eager to defeat her. To his surprise, Hela catches it in her outstretched arm, using her dark magic to manipulate the enchanted hammer, and then turns Mjolnir upon him.