Ultra Instinct Goku
Ultra Instinct,身勝手の極意 Migatte no Gokui in Japanese, literally meaning Key of Egoism, also known as Mastery of Self Movement and Secret of Selfishness, which is a very rare and highly advanced mental state. It is known among the gods for being exceptionally difficult to master, even for the gods.
In Dragon Ball Super during the Tournament of Power in the fight Goku vs Jiren(Dragon Ball Super episode 109-110), for the first time we can see Ultra Instinct Goku, which is supposedly called Ultra Instinct “Omen” Transformation, that enables him to use the Ultra Instinct technique, however, he has not yet mastered this form yet. He can only subconsciously activate this form after enduring prolonged stress against a stronger opponent and can only maintain it for a brief period of time before collapsing in exhaustion. When Goku enters this state, his hair is slightly spikier and more solid. His eyes take on a more stern, defined shape, sporting silver-colored irises. He also gains a complex silver, blue and purple aura consisting of rippling, fire-like energy, complete with sparkling particles travelling upwards much like Super Saiyan God before it.
Those who use the ultra instinct can automatically react to any threat without thinking about it and their body can adapt while in battle on its own. However, this ability is not an absolute guarantee against harms such as when Goku managed to bite Whis, to escape his hold and Whis can use Ultra Instinct. Moreover it does not make one completely aware of their surroundings that they can avoid specific hazards, even relatively harmless ones, like when Whis steps in poop while explaining the technique to Goku and Vegeta. According to Whis, while dodging and moving is easy to master, attacking while in this form is difficult as fighters are inclined to think about their attacks before making them, thus slowing them down and weakening their attack.
You can watch the fight Goku vs Jiren as far as it is below, including Ultra Instinct Goku Transformation and Ultra Instinct Goku vs Jiren Round 1:
Return of Ultra Instinct Goku
Goku transforms into Ultra Instinct “Omen” once again during his fight with Kefla, potara fusion character of saiyan girls from Universe 6, Caulifla and Kale. Their fight is spectacular as one of Kaioshins of other universe stated, but see it for yourself, Ultra Instinct Goku vs Kefla:
Ultra Instinct MEMEs
It came to my attention that Akira Kushida’s song played during Ultra Instinct Goku’s fight with Jiren or more of a rip version of it became widely used on youtube as background for remixed fights of other anime, cartoon or even movie characters, like the popular Ultra Instinct Shaggy:
Ultra Instinct Luffy:
Ultra Instinct Mr. Satan: