I recommend a look at the Parables section (middle chapters) of the Book of Enoch for an understanding of the Son before the advent. Throughout those chapters He was called the Son of Man, the Elect One, the Anointed. The chapters were not added by Christians as some suppose. Many scholars agree the chapters predate Christianity and personally I accept they are original work of the prophet Enoch. Then in chapter 105 (R H Charles translation chapter numbering) God calls the Anointed one His Son “I and My Son ...”. Daniel follows closely on from Enoch (even though, in my belief written thousands of years later but in prophetic continuity) and parallels passages such as the one where the man (actually this Son of Man before the advent) is led into the presence of the Ancient of Days. Ancient of Days or Head of Days is the phrase for the Father in both prophecies. Revelation likewise follows on from Daniel. Closely like Daniel follows from Enoch. The passage in Rev 1 describing the appearance of the Son of Man after the advent exactly follows the wording of Daniel’s description of Him before the advent. So the continuity is there from beginning of prophetic scripture to the end.
