Hard to say. You'd have to look closely at the story and the interactions between the characters to determine if that's the case. Maybe there are clues or indications throughout the manga that would clarify it.
My answer may confuse you. I understand that Battle Through the Heavens manga is different from the novel. The manga doesn't contain the H plot in the novel. The production and modification of the manga depended on the manga company's creative intentions and storyline. Whether or not the manga about the relationship between Xiao Yan and Medusa would draw this part depended on the manga company's arrangements and creative intentions. I hope my answer can help you.
I haven't read about the Battle Through the Heavens manga. H elements were usually used in comics to describe sexual elements to enhance the emotions and atmosphere of the story. The novel Battle Through the Heavens has also been adapted into various forms such as manga and animation. I'm not sure if there are specific rules or restrictions for the H element. You are advised to check the manga or related publishing or copyright information to find out if there are specific H element regulations.
My answer may confuse you. As a person who loves reading novels, I can't judge whether the manga contains the H element because this requires consideration of different authors and works. Moreover, the novel Battle Through the Heavens itself did not explicitly state whether the manga contained H elements.
The manga was usually created by the mangaka according to his own creativity and style. He might add some H elements or plot that was different from the novel. Therefore, if you are worried about the H element in the manga, I suggest you ask the manga author or the copyright owner to ensure that your rights are protected.
As for whether he would draw Xiao Yan and Medusa, it would depend on the manga author's creative plan and inspiration. At present, the specific plot of the Battle Through the Heavens manga has not been clearly revealed, so we have no way of knowing if the subsequent creations will include the plot of Xiao Yan and Medusa.
You could start with 'The Call of Cthulhu'. It's one of his most famous works. It introduces the terrifying and otherworldly Cthulhu entity and gives a great taste of Lovecraft's unique style of horror, with its blend of the unknown and the unknowable.