help is needed!!!!!

Which one is right to say "ich bin die Engel...." or "ich bin der Engel...."????
I know the article for the word 'engel' is 'der' but i'm not sure if it will remain the same in any cases, cuz i know the song from bushido says: "diesen Engel unter 1000 Huren" so i'm not sure about anything at all right now

I am THE angel = Ich bin der Engel
I am an angel = Ich bin ein Engel

die engel = angels
der engel = angel

I'm not a native speaker and still learning so there might be some mistakes

Also, next time post questions in the Speaking German/Learning German threads. new threads are mostly songs

oh and sorry as u can see i'm a junior member haha