I don’t know, the violence in DBZ is acceptable, it’s nothing too gruesome. With this it came off as psychologically uncomfortable as well, the kind of thing you’d expect to see in a Lars Von Trier movie. You have this guy with this creepy look on his face continuously smashing a characters head in as he squats on top of her almost dead corpse, with the ominous soundtrack in the background and creepy atmosphere. If I was a kid that shit would probably give me nightmares.
In any case the violence is purposeful
It’s unnecessary. Whether it’s there for a reason or not is not the point. Simply showing her begging for mercy and having him refuse and kill her off screen in any way would have served the exact same purpose.