The Asgardians of the Marvel universe regularly face unbelievably overpowering threats, from Fire Giants, to Dark Elves, to Celestials. Though they themselves are imbued with god-like powers, their arsenal must be up to the task, resulting in an impressive host of cosmic weaponry. Here are a few examples of some of the most powerful weapons available to the characters of the Nine Realms.
Thor's Stormbreaker
Though some may have expected the regular Mjolnir to feature on this list, it's arguable that the MCU's Stormbreaker surpasses the famous hammer in almost every way. Designed to be the greatest Asgardian weapon ever created, it sports increased range and power, provides for more effortless flight and allows its wielder to summon the Bifrost without the help of Himinbjorg, Heimdall's observatory.
In practice, it helps Thor defeat an army of Outriders almost single-handedly. He is also able to resist the power of the Infinity Stones long enough to wound Thanos. The comic version is a bit less powerful and belongs to Beta Ray Bill, but it is still a formidable tool in the right hands.
Surtur's Twilight Sword
The mythical sword of the Fire Giant Surtur is strong enough to doom all of Asgard, as told in the prophecy of Ragnarok. Forged from the remains of a galaxy destroyed by Surtur, the sword gives him the might to overcome all of Asgard, sending shockwaves through all the Nine Realms as he duels and defeats Odin.
If exposed to the Eternal Flame, the blade will become unconquerable, and it will be able to destroy all of existence, but Loki's plan to swap out the flame saves the day in the comics. The film version of the Twilight Sword also plays a similar role, as it succeeds in destroying Asgard after Surtur is reawakened by having his crown being placed in the Eternal Flame.
Jane Foster's Undrjarn
A relatively new addition to the canon, Undrjarn is Valkyrie's signature tool, formed from the surviving shards of the Ultimate Universe Mjolnir. Its unique properties as the so-called All-Weapon allow it to reconstruct itself into anything its wielder could desire.
In Jason Aaron and Torunn Grønbekk's Valkyrie: Jane Foster #9, Jane Foster uses it as a flail, a mace, a whip and finally a spear in her confrontation with Thor. However, its abilities don't stop there, as Undrjarn is also able to form the extinct White Wood of Feierheim, essentially willing the material back into existence.
War Thor's Ultimate Universe Mjolnir
Before it breaks apart and becomes Undrjarn, the Ultimate Universe Mjolnir was a mighty force to be reckoned with. The weapon of an alternate universe War Thor is claimed by Volstagg, seeking revenge for the horrific murder of a group of children who were under his protection.
The warhammer is able to obliterate the armies of Muspelheim and gives Volstagg the power to defeat both Enchantress and Ulik, who's cited as the strongest troll in the Nine Realms. While it certainly makes the member of the Warriors Three nearly unstoppable, it also feeds and amplifies his rage, causing him to become blinded by it.
Asgard's Destroyer
Originally designed to fight Celestials, the Destroyer armor is one of the most overpowered pieces of technology in the Asgardian arsenal. There is a tradeoff to accessing its immense abilities. Only a strong spirit can successfully pilot the armor or else they will be overpowered by its indiscriminate desire to demolish everything.
If successfully controlled, the armor provides ungodly strength and speed, close to complete resistance to damage and a beam that can penetrate almost any material in existence. Still, the longer one spends in the armor, the more susceptible they become to being overpowered by its sadistic urges.
Odin's Gungnir
Odin's most powerful weapon, the Uru-based Gungnir, is to the All-Father what Mjolnir is to his son. Though its exact origins are unclear, the spear has come to represent a symbol of Odin's rule as the hegemon of Asgard and as a formidable threat.
As it channels Odin's power, the weapon has been able to keep the MCU's Thor and Hela in check. In addition to giving Thor plenty of trouble in the few instances that the father-son duo have fought, the comic version of the spear is also responsible for banishing the thunder god to Midgard (Earth) in the first place.
Heimdall's Hofund
Heimdall's legendary sword is used primarily in his role as the gatekeeper of Asgard, but that doesn't mean it doesn't have a few tricks up its sleeve. The weapon is commanding enough to be able to channel the power of multiple stars, and it can be used directly against Thor.
It also assists Heimdall, and later Sif, in operating the Rainbow Bridge. It even possesses the power to disguise its user when needed. Though it can be destroyed by a force as powerful as Mangog, Hofund is too iconic and important to all of Asgard to overlook.