Although the creations and enchantments of Thor's weapons are different, the power levels they give the user are similar. It is confirmed that one doesn't have to be worthy to pick up Stormbreaker (which is how Groot managed to lift the head of the axe the stick).
Both Mjolnir and Stormbreaker were crafted by the Dwarves of Nidavellir, but Mjolnir was enchanted by Odin and Stormbreaker channels the power of the Bifrost. While Mjolnir required the user to be worthy, Stormbreaker simply requires someone who isn't a mortal to wield it.
Mjolnir is a hammer, and was enchanted by Thor's father, Odin, so that only those the hammer deemed "worthy" are capable of wielding or even lifting it. Stormbreaker is an axe, and although it does not have such a worthiness enchantment, its power is such that a mere mortal attempting to wield it would be driven mad.
Many viewers have pointed out that Thanos was able to lift Stormbreaker without a problem, but this is because the ax isn't enchanted as Mjolnir is. Others believe Thanos lifted Mjolnir (although briefly) and have even argued that he would be worthy of doing so.
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Why could Groot lift Stormbreaker?
During a Vudu Viewing Party for Avengers: Infinity War, co-directors Anthony and Joe Russo revealed a key difference between Thor's hammer Mjolnir and his new ax Stormbreaker: the latter doesn't require worthiness. That's why Groot was able to lift the ax, not because he was worthy but because he didn't need to be.
Although Stormbreaker and Mjolnir have very similar properties and powers, Stormbreaker is the most powerful weapon wielded by Thor so far. The obvious reasons are that Stormbreaker is the physically larger weapon out of the two, and not to mention that it is an axe, which could well be more dangerous than a hammer.
Because it could kill thanos, is more powerful and thor panicked. Had he thought to call Mjolnir thanks would have gone to catch it and it would have knocked thanos on his bottom or something similar. But because thor was reliant on stormbreaker because it was more powerful he did it without thinking.
In Earth-199999, Stormbreaker was constructed by Eitri as a replacement for Mjolnir. Its head broke in half when freed from the mold and the handle was not successfully constructed or available, but the handle was replaced and the head pieces reattached by Groot sacrificing his left arm.
Why does Thor love Mjolnir more than Stormbreaker?
Mjolnir was his first weapon and he was very attached to it. After all, Thor had the hammer longer than Stormbreaker. Korg: Sounds like you had a pretty special and intimate relationship with this hammer, and you losing it was almost comparable to losing a loved one.
The entire axe was undamaged by the beam from all six Infinity Stones. So the handle was likely enchanted alongside the head of Stormbreaker to be nigh-indestructible as well. After all, like other weapons of Nidavellir, Stormbreaker is a magical weapon.
There also appears to be some mental strength required too based on the end of Thor's warning, so that part of Steve didn't come from a bottle. The other aspect of Captain America that could explain his ability to hold Stormbreaker is that he also previously held Mjolnir.
However, if you mean comics Thor, he can destroy planets bare handed. His powers over the storm arent dependent on a hammer. If you mean the MCU, then I would have to say yes. Eitri stated that Stormbreaker was created to surpass every weapon made before it, and Odin stated Mjolnir's power was enough to destroy worlds.
But as it turns out, it was not just Thor's strength. After all, no weapon in existence should be able to stop the combined power of the Infinity Stones, no matter how powerful the wielder is. Turns out, Thanos was taken unawares. He had just incapacitated all the heroes who tried to stop him.
Mjolnir is not particularly heavy, it weighs 42.3 lbs. The fact that almost no one except Thor can lift the hammer has nothing to do with it's physical weight. The hammer is enchanted so that only those deemed 'worthy' are able to wield it.
Is it only Thor who can lift Stormbreaker? The answer is NO. Endgame has shown us that at least two types of personalities can lift Stormbreaker and negate the effects that will “drive one crazy and melt their bodies”.
Stormbreaker did not open the gate to eternity. It was manipulated to activate the bifrost , which was then used to open the gateway by directing the energy against the seal: The weapon may have displayed some levels of “feelings” against its owner, but Gorr has the powers of the Necrosword.
Stormbreaker survived a full blast from the IG utilizing all of its stones. Actually, not only did it survive, it overpowered it. Unless you think Hela's grip and innate powers is more destructive than all those stones combined then the answer is no, she can't destroy Stormbreaker.
As Thor described in Infinity War, Stormbreaker was a “Thanos-killing” weapon. Like Mjolnir, Stormbreaker is one of the most powerful weapons in the universe, and both Uru hammers nearly deal killing blows to Thanos in both Infinity War and Avengers: Endgame.
The movie doesn't explain Thor's motivations for giving up Stormbreaker, but it makes sense that Chris Hemsworth simply wanted Love to have a powerful weapon to aid her in battle. It's unlikely that he could give her Mjolnir, considering that so few people in the MCU have been deemed worthy of its power.
Due to it being composed of Uru, the weapon is nigh-indestructible and able to withstand energy blasts created by the Infinity Stones. It is also able to channel dimensional energy and summon the Bifrost Bridge, which enabled Thor to teleport himself, Rocket Raccoon, and Groot to Wakanda.
