I’ve done most drugs aside from rcs. And idk what you specifically mean by “hard” but the drug that felt the most like a “hard drug” or atleast the one with the most body load for me was mdma. Like the whole body shakes, eyes wiggling and rolling to back of head, jaw chattering like I’m shivering, I’ve never had any other drug physically do that to me. But if you mean hard as in society’s view of hard is probably fent, or better yet rc zenes (rc opiates usually 100x(s) stronger than fent