WARNING!!! my description contains 18+ stuff and a SA scene.

Genre: I think it was Seinen (it has to be) possibly with elements of horror, psychological and disturbing themes, I don't think it was hentai.

I read this manga/manhwa around 2012-2014

I think the MC was a photographer returning from a war, probably Vietman. It opens with the protagonist (or someone) having relations with a woman. In the story the people drank a soda/beer/juice in a can that make them hallucinate.

thats it, all the other stuff that I remember are random scenes like:

A girl is eating an ice-cream cone, a fly lands on it, she licks the fly, I don't remember if she did it on purpose or didn't see the fly. the panel of her licking the fly is a close up.

3 or 4 girl in roller skates make several appearances. They were topless in a scene.

A very horrific scene where some bad guy kidnaps a girl (probably MC girlfriend) and they force her to drink the soda, they SA her and she hallucinates that the guy doing the SA transforms into a tree-like monster, his member grows very big and tears the girl apart. Yeah. wtf.

Second manga/manhwa Genre: Seinen (again, it has to be) psychological and disturbing themes, kinda sci-fi.

this one is about a detective who is investigating violent crimes. In this world the people are addicted to a some sort of virtual reality game. I remember a scene where the detective explains why people who are addicted to this VR thing commit crimes. He says that when you are inside of the VR world and see a knife of gun or something like that is because the game wants you to use it somehow. so, when people go to the real world and see a knife think that is actually the game telling them to use the knife.

The only other scene that I remember is some kids playing soccer with something wrapped in rags, one of the boy kick the "ball" fall and its revealed that the "ball" is the head of another kid. The kids see the head and one say "this one is already damaged" and choose other kid to be the new "ball".

I thought the name of this manga was Eraser or Erased, but when I search for manga by that name I can't find anything similar.

Thats it, please help me. it's driving me insane.