AAAA yes!! This speaks to me and my little goth heart :')
I'm just gonna do an description of what I think Eldritch Sero would be, but feel free to request something more specific!
Submitted for the approval of the Midnight Society, I call this story, "The Tale of Shadowman Eldritch Hanta"
Hanta's form is hard to fully distinguish. Every time your eyes start to focus and recognize what you think must be his true silhouette, it warps and shifts into incomprehension again. What you can make out is inhuman height- he seems to stand at least eight feet tall as he looms in the shadows. It feels like he's staring at you, unmoving, unwavering. Not that you can really tell, you can't particularly spot any eyes of facial features.
He can feel your gaze though. Everytime you look at him, warm excitement courses through him, making his figure flicker slightly. You looked at him. You looked at him.
He doesn't interact with you at first. Hanta stays where he is for hours on end, just watching, just waiting for you to notice him again. It's understandably chilling to have him just lurking there. You adjust to it after a while though, surrendering to his gaze before simply continuing on with your daily life as if this curious mass wasn't constantly studying you wherever you go.
He can tell you've grown rather comfortable with his presence. It doesn't take long for him to grow comfortable with you too- this is when he starts to reach out to you. Small gestures begin to hint that he's trying to initiate more. Of course, small eldritch gestures aren't quite the same as human gestures. There are no flowers left on your doorstep or sweet letters of admiration, instead replaced with technological interference and a sheen of stickiness left on your doorknobs. He's more than relieved when you respond without anger or annoyance. Instead, you look for him again. You notice him again.
Hanta is a mischievous horror. Once he's sure you aren't going to run or fight him, his true demeanor starts to show. Things go missing only to return hours later to a place you're certain you looked, now covered in that now all too familiar stickiness. Startling you pleases him more than mere tricks though. He dares to leave his usual shadowy corner to stand right in front of you when you enter a dark room, only then revealing his seemingly disembodied orange eyes and a smile full of sickeningly sharp teeth. In that moment, he dares to reach for you physically and actually touch you. His touch feels impossibly cold, leaving you shivering in return. But to him, you feel just as soft as he knew you would.
The warmth you radiate, the silkiness of your skin, how soft and plush you feel compared to his incorporeal being- it draws him in even more. He longs to touch you again, to feel you again, to hold you. Would you ever want to hold him too?
Eldritch Hanta doesn't often take a more humanoid form. It hurts him both physically and mentally; it's as if he knows it just isn't how he's meant to be. If it means he could fully show himself to you though, it's a pain he's willing to bear. As long as you see him again.
Humanoid Hanta still doesn't look human. Sure he has all of the standard points of a human body- two arms, two legs, two eyes, one mouth- but he clearly isn't right. Oddly enough, he almost looks less human than when he's a mere shadowy silhouette lingering in the darkness. His limbs are thin and too long for even his tall height and he hunches over just slightly as if the weight of them hurts to carry. Orange eyes seem to glow as they bore into you. He works his jaw slightly as if his teeth don't quite fit in his mouth. Black stringy hair stays matted to his head, covered in the same sticky residue you'd begun to find around your house.
He doesn't speak; he can't speak. But there's something about his demeanor that let's you know he's waiting for reassurance. This more human form is just for you, after all, he does hope you like it. Do you like this better than the inky mist of his true form?
It hurts too much to stay like this for long, but he'll keep this form for as long as he can if that's what it takes for you to really see him. He doesn't want to be just a shadow anymore. Not when you're just starting to acknowledge him.