¿Who is stronger, Onslaught or Zamasu?

Onslaught is a comic book character created by Marvel Comics and is known to be one of the publisher's most powerful and feared villains. He is a cosmic being created by merging the minds of Charles Xavier and Magneto, two of Earth's most powerful mutants. Onslaught has a number of supernatural powers, including the ability to manipulate people's minds and behaviour, superhuman strength and the ability to manipulate magnetism. He is also virtually indestructible, making him a formidable foe for any hero who confronts him.

Zamasu is a significant antagonist in the "Dragon Ball Super" series, known for his complex ideology and formidable abilities. Originally a Kai apprentice from Universe 10, Zamasu becomes disillusioned with mortals, leading him to enact the "Zero Mortals Plan" to eradicate all mortal life. He collaborates with his future counterpart, resulting in the creation of Goku Black by swapping bodies with Goku. Their fusion through the Potara earrings forms Fused Zamasu, a being of immense power but with a deteriorating body due to the fusion of mortal and immortal entities. Zamasu's abilities include energy projection, flight, and a unique form of immortality. His character explores themes of justice, morality, and the consequences of unchecked power within the "Dragon Ball" universe.