The *soul* is 18, yes, but the text explicitly states the body he’s inhabiting is a teenager’s. The ML is an adult, who *does not know* Lingxi’s soul is 18, and is still attracted to the teenager he thinks Lingxi is. THAT IS PEDOPHILIA. Even if Lingxi is *technically* 18, it is just as creepy and pedophilic, because the ML doesn’t KNOW that, and still expresses physical and romantic desire/attraction to him.