(Dragon Ball Super Chapter 16)

When speaking to Zamasu, who respects the East Supreme Kai for having defeated Majin Buu, the East Supreme Kai inadvertently reveals the existence of one known as Goku, who transcends the gods, when he remarks, "Had it not been for Goku and his friends, we would have been destroyed by Babidi."

(Dragon Ball Super Chapter 16)

After learning that Zamasu had asked Zuno if "it's possible for a god to switch bodies with a mortal", the East Supreme Kai investigates future Zamasu using the Ring of Time.
He then tells Beerus that in the future, Zamasu switches bodies with Goku to become Goku Black and joins forces with future Zamasu to carry out The Zero Mortal Project.

(Dragon Ball Super Chapter 19)

The East Supreme Kai heads to the world of the future and saves Trunks and Mai, who have been driven into a corner by Goku Black and Zamasu. Afterwards, he entrusts the Potara Earrings to Goku, who's confronting Fusion Zamasu, and urges him to fuse into Vegito.

(Dragon Ball Super Chapter 23)

First Appearance

"Dragon Ball Super" Chapter 7

Trivia

In the world of the future, he manages to prevent Majin Buu from reviving!

In Future Trunks' timeline, the East Supreme Kai trains Trunks in the Supreme Kai's Realm to be able to defeat Babidi. Together with Trunks, he confronts Babidi, but runs into trouble due to Babidi's subordinate, Dabura. With the last of his strength, he puts Dabura in a hold, creating an opening for Trunks to defeat both Babidi and Dabura. Thus, by sacrificing his own life, he prevents Majin Buu's revival.