At the end of Episode 64 of Dragon Ball Super, it has finally happened. Zamasu and himself as Goku Black used the Potara earrings to fuse together to become one entity; which makes him into a Supreme God. Because Zamasu and Goku Black are essentially the same person, the name of the fusion character is just called Zamasu.
All of the existing Saiyan powers and immortality stay intact in this new form so both Goku and Vegeta will obviously get overpowered in Episode 65. When Vegeta and Goku finally decide to do fusion to become Vegeto, that’s when things will get Super interesting. Enjoy the video clip of Zamasu doing fusion below.