/vt/ - Virtual Youtubers

>>70988354
It really depends on how hard you want to go.
20%: eyes, (look to dslr lenses for inspiration) robomimi, antenna, at this point, aside from some minor oddities, they still look "human"
40%: Hereabouts is when you start getting "robot girls", obvious joints, panel lines, inhuman accenting, they're clearly not "human", but wouldn't be noticeable from afar, and can take steps to pass for human close up. Aigis from p3 is a good example.
60%: Clearly not "human", even at a casual glance, odd-colored skin/hair, abhuman proportions, generally the only thing that's definitively attempting to be "human" is the face, everything else is just approximate. Sonny from the film version of I, Robot (read the short stories instead) is a good example, if he wasn't so fucking bald
80%: drossel, tv-heads, an effort is made to hew to the "human" bodyplan, but nothing that could be mistaken as organic. This is generally what westerners go for when they design a "robot girl", but winds up being much more robot than girl
100%: EVA from wall-e, generally it's going to be smooth lines and flowing form that marks them as "female", but only in an abstract sense

>>70990293
From what you've said, you're probably looking for something in the 40% range. For a vtuber design specifically, you'll want something like picrel, and since the goal is "human turned into cyborg/robot" extra attention should be paid to the neck and how it would interface with/carry a human brain (unless the brain is hidden away in the chest cavity for safety)