From Halopedia, the Halo wiki
Echo Six was a codename for an Orbital Drop Shock Trooper in Echo Team of the 340th ODST Combat Training Unit stationed in the Special Warfare Center in Seongnam on Earth during 2552. He, as well as several others from his unit, participated in the testing of the MJOLNIR Mark VI PAA.
In October 2552, Spartan-II Maria-062 was sent in training with Echo Team. During the armor test, SPARTAN-062 hurled a paintball grenade onto the middle of the unsuspecting ODSTs, neutralizing Echo 1 through 5. Echo Six was the only one left standing and immediately proceeded to run. However, he or she was quickly incapacitated by Maria-062, but not before initiating the "Bulgoki Gambit". After SPARTAN-062 was finally subdued by members of Kilo Team, she was brought back to the Special Warfare Center, accompanied by Echo Six and the rest of the ODSTs (whom all had paintball marks on them).
List of appearances