Zamasu

Zamasu (in Japanese: ザマス) is the main antagonist in the Future Trunks Arc of Dragon Ball Super. There are two different timeline versions of him working together to kill all of the mortals in the multiverse - Goku Black and Future Zamasu.

Zamasu was formerly the North Kaio of Universe 10 and the apprentice of Gowasu, the Kaioshin of Universe 10. He holds an incredibly black and white viewpoint, believing that the gods are all good, whereas mortals are evil and need to be wiped out for the good of the multiverse.

He was voiced by Shin-ichiro Miki who also voiced Mizuki.

Personality
While a man who cares for the development and prosperity of the universe, the present Zamasu often questioned the worth of humanity, not trusting in their ability to handle conflict, as they were prone to commence war in a repeated cycle. He also did not agree with how the Kais would not be more directly involved in mortals' actions, like the Gods of Destruction. Despite this, he acknowledged his lack of personal experience and was willing to diligently listen to his teacher Gowasu's words. To which, he was a humble, ordinary, deferential, and level-headed man with just goals, as Gowasu noted by how well-balanced he would brew tea, implying that he was a just and honorable man. In battle, he is shown to be a very calm, regular, and methodical fighter, carefully perceiving his opponent's attack style and seamlessly countering in a fluid manner.

However, after meeting Goku, his views radically changed, and his distrustful and depreciatory nature towards humanity only grew. Annoyed at Goku's carefree attitude and lack of respect, his distaste for the gods not quelling the dangerous nature of mortals evolved to a radicalism-level. Shocked at how a mortal like Goku could gain a power rivaling gods (or even obtain such power to begin with) and so recklessly challenge one, Zamasu came to sternly believe that humanity by nature is an evil.

However, the future version of Zamasu has truly fallen into the depths of evil, speaking of humans and of the Saiyans as "mere humans" who are inferior to him. Similar to his partner, Goku Black, he has a sadistic, merciless, and unpleasant goal of ridding the entire universe of humans in the name of "justice", believing them to be the source of all evil, and he refers to a world without them as a "utopia". Future Zamasu also seems to have a deep hatred for Goku, as he considers killing him as his main goal and something only he should do (a trait his past counterpart is slowly developing). While battling Goku and Future Trunks, he constantly speaks about how humans misuse their "god-given wisdom" for their own personal gain. Also, Future Zamasu refers to his immortal body as befitting for him.

Zamasu is also extremely selfish, petty, narcissistic, vindictive, treacherous and highly hypocritical about his goals and views on mortals and how they should be dealt with.