The user is able to enter a state which allows limitless, godlike abilities, skills and traits making them nearly unstoppable with capabilities and powers that transcend all of the users basic limits whether physical, spiritual, mental, etc. With this power the user may gain virtually any kind of supernatural powers to the point of making them Nigh Omnipotent.
Controlled God Mode:
Users that possess control over this mode will be able retain their thought in the process, and not go berserk, while possessing the same or more level of godly strength and power to defeat their target.
War God Mode:
Most users lose their sense of humanity and goes berserk, making them ominous and evil. Their physical capabilities (strength, speed, and healing) increase drastically, allowing them to deal out devastating attacks while shrugging off horrific injuries with only one goal to defeat their enemy.
Asriel Dreemurr (Undertale); after transforming into the Absolute God of Hyperdeath
Divine Murakumo (Valkyrie Crusade)
Fei Fong Wong (Xenogears); after becoming the Perfect Contact
God-Tier Users (Homestuck)
Asura (Asura's Wrath), having ascended to true godhood, as Asura the Destructor.
Aang (Avatar: The Last Airbender) in the Avatar State after unblocking his chi.
Korra (Avatar: The Legend of Korra) entering the Avatar State.
Lille Barro (Bleach) gains godlike powers upon activating the true form of Jilliel.
Yhwach (Bleach) became a godlike being after killing and assimilating the Soul King.
Wonder Woman (DC Comics) can access her godly abilities by removing her gauntlets.
Batman (DC Comics), the God of Knowledge.
Superman (DC Comics), the God of Strength.
Hal Jordan (DC Comics), the God of Light.
The Flash (DC Comics), the God of Death.
Lex Luthor (DC Comics), the God of Apokolips.
Shazam (DC Comics), the God of Gods.
Whenever a Saiyan (Dragon Ball series) is fueled by the power of six pure-hearted Saiyans, he/she is able to access a powerful form of legendary status, Super Saiyan God - Son Goku is the second Saiyan to achieve this form.
After obtaining godly Ki and mastering it, Son Goku and Vegeta (Dragon Ball Super) can fuse it with their Super Saiyan transformations, allowing them to become Super Saiyan Blues...
...with Vegeta training under Beerus to acquire the Ultra Ego form, enabling him to gain the powers of a God of Destruction...
...and Goku obtaining the Ultra Instinct form to enhance his power even further...
...and like his fusees, Vegito can also become a Super Saiyan Blue...
...As does his counterpart, Gogeta.
Goku Black (Dragon Ball Super) as a Super Saiyan Rosé, his equivalent of the Super Saiyan Blue form.
Top (Dragon Ball Super) as a God of Destruction Candidate can transform into one and gain all of the abilities of one.
Renya (The Guided Fate Paradox) uses his God Mode for the 1st time.
Iris Heart (Hyperdimension Neptunia) is Plutia's God or Hyper Divinity Drive form.
Natsumi Rokudo (Jungle de Ikou) can become Mii, a fertility goddess.
Link (The Legend of Zelda series) is in the form of the Fierce Deity, granting him power surpassing that of Majora's Mask.
Medaka's (Medaka Box) Altered God Mode.
...and Hybrid God Mode.
Zenkich's (Medaka Box) Altered God Mode.
After receiving chakra from the Sage of the Six Paths, Naruto Uzumaki (Naruto) could transform into his Six Paths Sage Mode.
Reinhard Heydrich (Shinza Banshou series) unlocked his Atziluth, becoming a Hadou god.
Ren Fuji (Shinza Banshou series) unlocked his Atziluth, becoming a Hadou god.