The user is able to draw strength from powerful divine forces of different gods in order to increase their natural abilities. Often times, this occurs when one gives prayer to the gods, comes in contact with a relic of their power, or becomes a conduit of their energy. If the user is deemed worthy, they may be able to keep the powers they are blessed with.
Satou Pendragon (Death March to the Parallel World Rhapsody)
Stephen Strange/Doctor Strange (Marvel)
Sophitia (Soul Calibur Series)
Vehrn Juonour El-Ganobyi (MARDEK); via Green Lightning
Nora (Islands of Wakfu)
Jack (Samurai Jack) prays to the great ancestors to enhance the power of his sword in order to vanquish the Ultra-Robot.
Ryu Hyabusa (Ninja Gaiden series) is able to enhance the strength of his Dragon Sword with the Dragon Eye, a magatama gem that is infused with the soul of a mighty dragon spirit.
Like many other witches and wizards, Willow Rosenberg (Buffy the Vampire Slayer) often has to invoke gods to perform feats of magic.
Thor's (Marvel) God-Force is what fuels his powers and is even stronger than that of Mjolnir, allowing him to access of his incredible powers regardless of what realm he is in,
Kratos (God of War) wielding the Blade of Olympus, a weapon forged by Zeus to end the Great War. The sword possess the very power of Olympus and it is used to strike down those who defy the gods.
The Sacred Flames (Legend of Zelda: Skyward Sword) are mystic and powerful fires of the golden goddess's, Din, Nayru, and Farore. Each time Link bathes the Goddess Sword into the flames, the become stronger, until it finally evolved into the one and only Master Sword.
The Master Sword (Legend of Zelda series) in its true form after being blessed by Hylia's mortal form, Zelda.
Storm (Marvel Comics) invokes the African deities to strengthen her weather powers.
After using the Eye of Odin, Goliath (Gargoyles) became an avatar of Odin himself.
Nora the Eliatrope (Islands of Wakfu) and her dragon brother Efrim.