‘Field Marshal’ Heta Kol, is the leader of the disenfranchised Mandalorians naming themselves the ‘Hidden Chain’.

Heta Kol grew disgrunted at Shae Vizla’s leadership as Mandalore the Avenger. Believing that Shae had lowered the united Mandalorian clans down to the level of weak ‘mercenaries for hire’, working for anyone except themselves as an independant force of power in the galaxy.

Kol found support with the Mandalorian Clan Varad, as well as both the Ash’ad and the disgraced Mek-Sha Dar’Manda, where she united them and lead warships against the Spirit of Vengeance, a Mandalorian flagship of Shae Vizla’s. While she was not successful in total domination, they managed to steal the banner of Clan Cadera, a worthy trophy in aid of rallying recognition to the cause of the Hidden Chain.

Currently, Shae Vizla and the Eternal Alliance are tracking the exploits of Heta Kol and the Hidden Chain across the galaxy but have yet to find them or return the banner of Clan Cadera.

“In Shae Vizla, I see only hypocrisy. She has driven out those who oppose her view, yet she has remade the Mandalorians into servants of anyone who pays her enough credits–no matter what they believe. Where is the honor in that?”
-Field Marshal Heta Kol


Sources:
Game Update 6.2 – Echoes of Vengeance:
Spirit of Vengeance – Onslaught Storyline
Field Marshal Heta Kol – Codex Entry