From Halopedia, the Halo wiki
This article is about the entity mentioned in Halo Infinite. For the Halo 5: Guardians achievement, see Harbinger (achievement).
The Harbinger is an entity of some form, active in the year 2560. The Harbinger was apparently allied with the Banished, according to Escharum, who claimed that the Harbinger and the Banished both fought in the name of Atriox.
List of appearances