DBS Interval special, Goku's ultimate form and the realm of the Gods.

In the history of Dragon Ball, Goku has trained under many martial arts masters but in DBS its the training under the Angels that allows him to gain access to the ultimate technique Ultra Instinct.
(DBS Manga Goku's Master and Student Interval Special Vjump Text)
In "DB Super", Goku continues his quest to reach even greater heights, and aims to perfect Ultra Instinct which is the realm of the Gods! He gets assistance from his new masters!
Goku learns about the realm of the Gods from his encounter with Beerus, the God of Destruction. After that encounter he studies under the Angel Whis, who is Beerus attendant and master. He began training to master Ultra Instinct.
Merus who is a member of the Galactic Patrol and has a secret, is also Goku's master. Only thanks to his presence was Ultra Instinct completed.
(A look at Ultra Instinct)
Ultra Instinct was perfected in the fight against Moro. It is the ultimate technique in which allows the body to both evade and attack on its own.