eventually only Nii-SAN is normal

No. I would say that you're as if comparing a poisonous snake with a venomous snake. Nii-san was unethical, I mean forcing rape on children is fucked up. (Disclaimer: I'm aware it's fiction.) But then, manipulating people is also fucked up as well. I mean, the degree of fucked-up-ness between these two manga are similar but very different and distinguishable.

Normal? I don't think it justify that.

however , don't you think the color recipe's final chapter is more SHOCKED than any other chapter else?