The 'Obey Me' manga and its BL version share many similarities. The BL version might emphasize certain romantic elements more, but it still builds on the foundation of the original manga's world and characters. Some fans might notice minor differences, but generally, the essence is preserved.
Sorry, my answer may not be clear enough. If you ask the manga author if he would draw sequels or derivative works of the same work, the answer is no. Most manga authors would set a clear storyline and ending for their works and would not draw sequels or derivative works. This was because comics were a commercial activity, and authors would usually obtain economic benefits through the sale of copyrights. Sequels or derivative works might violate the copyright of the original work, so they were not accepted by the author.
The 'obey me novel' often involves a story where the protagonist is immersed in a world full of demons. There are various characters with unique personalities and powers. The plot usually includes elements of the protagonist's interactions with these demons, building relationships, and dealing with different challenges and mysteries in this otherworldly setting.