Commenting on Rev 14:6, Victorinus offered the following commentary, showing his belief in a then-future coming of Old Testament Elijah ("Elias"):
6. “And I saw an angel flying
through the midst of heaven.”] The angel flying through the midst of heaven,
whom he says that he saw, we have already treated of above, as being the same
Elias who anticipates the kingdom of Antichrist in his prophecy. (ANF 7:357)
Further Reading:
Refuting the Tanners on the LDS Interpretation of Malachi 4:5-6
New Testament and Early Patristic Expectation of a Future Coming of Elijah