Weird thought came to mind but, I can envision this VN to be a fleshed-out game to that of Dynasty Warriors. Having to fend off hoards of Monsters to protect your home and allies, relying not only on your mana vision to look for weak spots and openings but also on your friends to unleash powerful attacks to gain the upper hand in battle. Strengthen your bond with your friends by engaging with them both inside and outside the battlefield. Doing this not only reinforces one's attacks and combo potential but also allows the protagonist to share more intimate and sentimental values. Of course, the game would be story first gameplay second, but the way you incorporated mana into your story undoubtedly has potential.