Goku Black arc was dark though. You got fucking people stabbing through bodies and shit, Goku's family dying and losing his body, Trunks's entire family pretty much dead, and literal child murder. The ending was just disturbing, Trunks basically lost everything that made up that Universe, and now has to live that guilt of not being able to save the world and not living up to the promises he made to those kids (Who are dead btw). All that work Trunks did to seeking help from the past and the Time Machine was all for nothing. In technical terms, Zamasu won. The fact that he died doesn't mean shit since he succeeded in eliminating all mortals, which was his end goal. The first time in a series where a villain actually wins.