The Ascalon (Ben 10: Ultimate Alien) was a powerful sword created by Azmuth. The sword is able to the forces of the universe itself as the source of its power.
The Dark Knight Sparda (Devil May Cry) is a legendary demon who once wielded the weapon named after him, an indestructible sword imbued with his own demonic power.
By surrounding his hand in his Godly ki, Zamasu (Dragon Ball Super) can create God Split Cut, an energy powerful enough to kill large beings and gods.
Goku Black (Dragon Ball Super) can use Godly ki to create Violent Fierce God Slicer, a more powerful variation of Zamasu's God Split Cut.
Goku Black can can shape his Violent Fierce God Slicer into the more powerful Azure Dragon Sword Model Energy Blade, which fires piercing exploding energy needles.
In the final battle with Fused Zamasu, Future Trunks (Dragon Ball Super) was able to channel the hopes and energies of everyone alive on Earth, along with the power of Goku and Vegeta, changing his Light Sword in the Sword of Hope.
While his quest to kill Ares, Kratos (God of War series) was given Blade of Artemis by the Goddess of the Hunt Artemis, a large curved sword surrounded by raw energies, allow it to pierce armor easily damage any enemy.
The Blade of Olympus (God of War series) is the most powerful weapon in the world, created by Zeus to end the Titanomachy.
Ryu Hayabusa (Ninja Gaiden series) wields of the Dragon Sword, blade carved from the fang of a Divine Dragon and imbued with the essence, souls, and spiritual power of the twelve Divine Dragons. Combined with the Eye of the Dragon, it transforms into the True Dragon Sword, and can kill supernatural beings and supreme deities.
Genshin (Ninja Gaiden series) wielded the Blade of the Archfiend, a sword rumored to have been forged from a meteorite infused with the Archfiend Vazdah's demonic magic.
Thanks to his will to never give up, Sonic (Sonic the Hedgehog series) rekindled the long lost light of Excalibur and managed to draw the power of the sacred swords, allowing Sonic to become Excalibur Sonic and Caliburn to become the legendary Excalibur.
Nightmare (Soul series) wields the demonic sword Soul Edge. The sword was once an ordinary weapon until became bathed in the blood and hatred of numerous wars, turning into a powerful demonic weapon with the demonic Inferno as its soul and asborb the souls of other to increase its power.
Link (The Legend of Zelda series) wields the Master Sword. The Master sword is the Blade of Evil's Bane, infused with the sacred flames of the Golden Goddesses and blessed with Hylia’s power in order to strike down even the greatest of evils.
The Ame-no-Ohabari (Highschool DxD) is the most powerful divine sword of Shintoism, having been used to slay the Fire God Kagu-tsuchi...
...which is later sealed into the Longinus Canis Lykaon, granting it the power to create god-slaying blades.