Canonically we know that Kratos has been buying armor, equipment, and getting upgrades from Brok and Sindri throughout God of War 2018.
The Leviathan Axe is Canonically More Powerful than Mjolnir.
Originally designed for Laufey, Kratos' wife, the Leviathan Axe is meant to be equivalent to Mjolnir, which Brok and Sindri created as well. This weapon is the guilt they feel after Thor's massacre of the Giant people, inspired by the epic size of the World Serpent with the power to oppose Mjolnir.
As it turns out, the two weapons are actually very closely related in God of War's version of Norse mythology. Like Thor's hammer, Kratos' axe has the ability to return to its user's hand when thrown. Likewise, both weapons are magically infused with a certain element.
God of War's combat is impressive, and while Mjolnir could have been a worthy addition to Kratos' arsenal, it wouldn't fit the character's arc based on William's logic. The Norse Saga has transformed Kratos from a ruthless and bloodthirsty anti-hero to a protagonist with real depth.
Prior to the release of God of War: Ragnarök, many fans found themselves thrilled at the idea of using Mjölnir after defeating 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.
It was tough to put Mjolnir above the Blades of Chaos. We never got to see it in action during God of War so the legends have to speak. Thor used Mjolnir to kill all of the giants, which was no doubt a difficult task. Mjolnir also increases Thor's ability to control electricity, rain, wind, and thunder.
Unfortunately for fans looking to pick up the iconic hammer, neither Kratos nor Atreus can wield the mighty Mjölnir in God of War Ragnarok.
In the Novel, it was revealed that the Blades of Chaos were forged by Hephaestus, but in the first game, it was mentioned that they were made in the Underworld by Ares.
Max Level Of Leviathan Axe
As mentioned earlier, the Leviathan Axe starts off at level 1. But through the upgrades, you can take the Leviathan Axe all the way to a max level of 9.
The Winner: Old Kratos
Old Kratos from the Norse God of War games takes the trophy for the strongest Kratos.
Kratos' rage, arguably his greatest strength (as we just saw, it allowed him to literally get out of the Underworld), is also his greatest weakness. Sure, in-game, Kratos' Spartan Rage is incredibly powerful, and to anyone who's played the games, it's probably gotten them out of a few tough spots.
Mjolnir, the Mystical Uru Warhammer
Mjolnir was forged for Thor Odinson's grandfather by the dwarves, who used the core of a star and Uru metal to form the iconic hammer and imbue it with its immense strength and magic. It is nearly invulnerable and is capable of great destruction.
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.
During the boss battle that follows, the Leviathan Axe proves to be a worthy match for Mjölnir, clashing with the hammer without shattering and even freezing a massive bolt of lightning solid when it collides with Mjölnir in midair.
It's an interpretation of when he flipped Tyr's temple. Some people took that as him actually lifting and flipping the weight of all nine realms.
And Mathaudhu can cite documentary sources to back him up. For example, Marvel – which publishes the Thor comics – issued a “Thor's Hammer” trading card in 1991 that states Mjolnir is made of Uru and weighs precisely 42.3 pounds. That's lighter than a herd of 300 billion mice, much less a herd of 300 billion elephants.
Believe it or not, we actually know exactly how tall Kratos is thanks to this oddly detailed technical breakdown video from Santa Monic Studio's Axel Grossman. Kratos is exactly six feet and four inches tall (or about 1.93 meters, if that helps) in God of War: Ragnarok.
Doctor Doom
Not everyone who has lifted Thor's hammer was worthy to hold Mjolnir. A perfect example of this is Doctor Doom, one of the world's most dangerous villains. While Doctor Doom is a master of magic and science, it was his luck in finding the hammer that allowed him to wield it.
The Blade of Olympus is a powerful sword with the unique ability to hold power in reserve, but it's one of the most iconic weapons in the franchise because of the role it plays in vital story moments. With the Blade of Olympus in hand, Kratos changed the world.
Despite having every opportunity to take Thor out once and for all, the once rage-consumed Ghost of Sparta has turned a new leaf. He instead spares Thor and seeks a mutually beneficial relationship in which, together, they take down Odin. Sony Kratos ultimately gets the best of Thor at the very end of Ragnarok.
The Leviathan is a two-handed war axe that is Kratos' main offensive weapon in God of War.
No matter how powerful a foe is, Kratos has always found a way to kill them. This is something that Thor simply cannot match, and could give Kratos the advantage he needs to defeat the God of Thunder in combat. After all, no other god has been able to stand up to Kratos and ultimately live to tell the tale.