I just wanted to chime in with agreement on these points.
Also, it's Raze, not just any demonspawn. He had his very important romance arc with Bright if you chose him as a LI; or he was betrayed by her when he was trying to find some sort of redemption/understanding through her after all the trauma he went through in his childhood. This game takes place a century after the original events, if I'm understanding the timeline properly from things said so far. If Bright was romanced and managed to live a long life thanks to her demon heart keeping her in better health than most humans, and given she was 18-19 during her games, she's likely only been dead from old age a couple of decades. For some, that might be enough time to grieve- but for someone as emotional and attached as Raze was, who couldn't imagine a life after her and didn't want to think on it, he'd likely still be in a bad headspace during this installment. Which might contribute to his current actions (though I'd hope after the BS with big brother Thayne and his lies- and real!Raze going apocalyptic in rhetoric, he's learned his lesson about other demonspawn with grand designs). If he was unromanced and betrayed by Bright, well then he's likely to be very bitter towards humans. Neither option spells romance potential for him, especially when there's no mental health services to try helping him; and he really needs to be shown working out his mental shit first. There's a wide world of demonspawn running about to ask for romancing potential with, it's indicated in Hunters that Raze and Thayne's father was particularly prolific in spawning and they have several other brothers, but I don't think Raze himself is a great option at this time.
I hope Lamb sticks to what feels right when writing this story. Would a demonspawn be nice to romance? Yes. The potential new stories that could unfold are always intriguing. But I'd rather have a well written story with a great deal of choice within the options for romance offered than something shoehorned in for fan service. Trying to force fanservice moments that go against the creator's intended narrative is what deteriorates a series in quality, it can undermine the overall world built. There's always potential for a next installment to have demonspawn romance shenanigans, while this one does its own thing and expands the world/lore of Demonheart in hopefully satisfying ways.
But a (hopefully helpful) suggestion for Lamb- as a demonspawn, especially Raze, is not among the featured LIs, maybe contract a cover art picture that features the protagonist and/or her actual love interests. Having Raze front and center as the face of the game, pleasing as he may be to look at, may lead folks to have false expectations about just how much they'll get from him in romance potential and lead to disappointment/negative feedback. I know artwork, especially quality artwork, is an expense not lightly overlooked in the development process (particularly for smaller developers), but if it helps avoid confusion and downvoting on the game, it might be worth it.