know A-tan is probably tired of being asked to watch this-and-that series, but since FlavoryFantasy has thrown it out there so I'll just say; I give my fullest-maximum-absolute support for you to try Horizon !
Have you watched "My Grandfather Fought Vampires and Now I Have to Defeat Super Vampires with My Breathing!" ? It's a sequel of "My Childhood Friend Turned Into a Vampire With This Stone Mask and Now I Have to Defeat Him with My Breathing!". I heard it's suffocatingly moe.