https://www.pcgamer.com/why-people-love-nier-so-damn-much/
Yoko Taro
producer Yōsuke Saitō
This all started with Drakengard, Yoko Taro's first game that was released on the PlayStation 2 in 2003. If Nier is merely strange, Drakengard is fully batshit. It's hard to explain it without going into intense detail about the lore, but what sets Drakengard apart from other RPGs is just how bone-chillingly dark and twisted it is.
Do you want some examples? Okay, you asked for it:
What's key about Taro is that, even if his intentions seem impossible to divine, there always some kind of logic to it.
One of the main characters is named Leonard and he joins the party shortly after his three kid brothers were butchered by soldiers while Leonard was off in the forest masturbating to the thought of little kids. Yup, he's a pedophile and is very torn up about it. He tries to kill himself but a fairy shows up and manipulates him into forming a magical pact with her in exchange for his eyeballs.
Another main character is an elven mother driven insane by the death of her child. She slaughters and eats children because she thinks she'll be able to "protect" them inside of her womb. In one of Drakengard's many different endings, she is eaten by a horde of giant celestial babies. Now that's poetic justice!
In one alternate ending, the main character's sister commits suicide because it's revealed that she harbors incestuous feelings for him. It's not clear if he reciprocates, but I doubt it because he's clearly in love with his pet dragon that also stole his ability to speak.
In Drakengard 3, the main character was sold into prostitution as a child but is also a divine songstress on a mission to slaughter her five sisters and bring about the end of the world. She also has a flower growing out of her eyeball and rides a dragon with the voice of a child. Each time she kills one of her sisters, she forces their disciples to become her sex slaves. There's a cutscene where she explicitly tells one to prepare for sex by washing "front and rear," so you know she means business.