Why did Stormbreaker was asked by Thor from Captain America in Avengers: Endgame’s final fight?
For the simple reason that Odin’s spell enchants Mjolnir, As Cap is worthy, while using Mjolnir, he would also have a fraction of Thor’s powers.
If he used the Stormbreaker, it would function as a regular axe.
To understand it in detail, it all comes down to the significant difference between Stormbreaker and Mjolnir, which Odin’s spell makes.
Stormbreaker
- Made of Uru Metal
- Created by Eitri, the dwarf
- Can summon Bifrost
- Not enchanted by any spell
- It doesn’t require anyone to be worthy
- Anyone can lift it (Rogers, Thanos, Skrulls)
- Anyone can use it (But only as a normal axe)
Mjolnir
- Made of Uru Metal
- Created by Eitri, the dwarf
- Can’t summon Bifrost
- Enchanted by Odin’s spell
- Requires the person lifting it to be worthy
- No one else can lift it
- Only the worthy person can use it (this person will now have the power of Thor as per the spell)
You see, anyone can live the Stormbreaker in the MCU. That includes Thor, Thanos, Gorr, Iron Man and even the Skrulls. But only Thor can use it as a ‘Thanos killing weapon’.
Thor is so powerful that he needs his energy channelled somewhere, and that’s when Strombreaker comes in. Thor is the source of power while using it. That’s how he could withstand the power of all the infinity stones combined.
Steve Rogers or a Skrull (used as an example for this answer) might not possess any powers whil using Stormbreaker. For someone else, it’s just a normal axe that they can use to chop wood logs.
