Possibly a demon? something worse?

Ok for starters I don't want to hear any bull**** about it not being real because did I ask if it was real? NO ok now that we got the clear my friend and I were at school she was telling me about this grave they found in her front yard she sent me pics (which I can't upload do to phone difficulties) so anyway she said a lot of weird things have been happening lately she heard voices oh and this whatever screamed the name rose when she was in her room so she told me the thing said its name was Z yes just z she said he comes into your dreams so that night I had the most HORRIFYING dream I was running and was picked up and thrown against the wall when I asked who are you it wrote on a mirror in black ink Z that morning when I woke uhp my back was hurting I had a scratch all down my leg and my arms were bruised and whenever I'm on the phone with nataly aka rose I heard screaming loud doors and voices other than hers and I know it isn't anyone else because she stays at home buy herself during the times we talk until her parents come home from work last night I saw a strange black entity or shadow I really don't know if thisis a demon or just my imagination but I have a feeling whatever it is isn't leaving sometimes this thing follows her home sometimes it follows me home it has screamed at me in my head before I worry that something bad is going to happen I have had paranormal experiences before so I know when something isn't right I have heard that it has something to do with religion? Well I have NO religion no I am not an aethist aeithist idk nor do I worship the devil I have been having phenomonas everyday since then this has been going on for at least 4 months I am not scared of this thing but do I like it? No I don't want to get rid of it I just want to know how to classify this thing because it isn't a host in my house it is emotionally and physically attached (have a.d.d.) he has abused me through her body he has scratched me I find z's on my body everywhere