The Crystal Harbingers are a thrallband of the Thousand Sons Traitor Legion. The Sorcerers of the Crystal Harbingers delve into the hidden recesses of the Silver Towers to explore the Tzeentchian labyrinth to which they lead. Here they glean portents of the future and commune with daemonic entities, which they then use to terrifying effect in their wars against the forces of the Imperium.
The Crystal Harbingers' colours are cobalt trimmed in bronze. White robes and tabards are often worn by members of this thrallband.
The Crystal Harbingers' sigil is a white coloured sigil of the Cult of Prophecy in the form of a stylised eye, centred upon a field of cobalt trimmed in bronze.
- Codex Heretic Astartes - Thousand Sons (8th Edition), pg. 21