Locutarus were specialized troops used by the Ultramarines during the Great Crusade and Horus Heresy. These elite troops were maintained by most Chapters within the Legion in small numbers for use in vanguard and strike operations. Each Locutarus had been selected from Assault Squad veterans.
During pitch battles Loctarus Storm Squads were often held in reserve, being deployed by their commanders only at the perfect moment of attack. They were very well equipped for this role, utilizing artificer-wrought Power Swords.