Koike Keiichi's works. His manga is visionary art. And it's no wonder, this is what he said in an interview: "except peyotl, I have tried almost everything: hashish, heroin, cocain, acid, magic mushrooms... From a strictly graphical point of view, however, LSD is most important by far...". Gantz Waiting Room is in the process of translating more of his oneshots.
Ultra Heaven is his most popular one.
https://mangadex.org/title/1120/ultra-heaven
Not all of his stuff is translated, but Gantz Waiting Room will eventually do them all. One of them will probably get released this month.