Decanus Severus

Decanus Severus is Aurelius of Phoenix's second-in-command, living in Cottonwood Cove in 2281.

Background
Originally the leader of his own contubernium assigned to the cove, Severus transitioned to the role of quartermaster when centurion Aurelius of Phoenix arrived. Beyond taking care of the stocks of equipment and dealing with any captured gear, Severus also coordinates Legion patrols. The biggest problem is not the fact that the NCR avoids engagement with Legion raiding parties, particularly after the fall of Camp Searchlight, but the land mines the Army liberally peppers over the countryside to curtail Legion operations. The Legion has yet to develop a reliable method of disarming them.

Quests
Arizona Scavenger: The player character may trade NCR dogtags to him for food, weapons, armor, or ammunition and Legion fame after passing a Barter check of 35 with Aurelius of Phoenix.

Other interactions

 * If one has 50 Explosives skill they can tell Severus how to disarm NCR frag mines. This will earn experience, and +2 to Caesar's Legion fame. This can be repeated numerous time by simply asking about "Do you see much action against the NCR?" then saying "That is all for now." Then choose the text option of "I can show you how to disarm the NCR's mines," with passing the Explosive skill check and repeat the process.
 * If one has the powder charge schematics, they can teach Decanus Severus to craft them for +4 to Legion fame. The schematics for building powder charges can be found in cell block B of the NCR Correctional Facility on the first left top bunk inside the first locked cell on the left.

Legion Fame
Due to several bugs with Severus' dialogue, turning in dogtags five at a time in exchange for food will yield the most fame per tag, granting +12 Legion fame for five tags. Turning in 25 dogtags five at a time is sufficient to become Liked, 10 for Accepted and 5 for Neutral. Turning in 40 tags five at a time, followed by another 3 tags in one set of three will grant the Courier Idolized status with the Legion.

Appearances
Decanus Severus appears only in Fallout: New Vegas.

Behind the scenes
In Latin, decanus refers to a military rank of "a commander of ten soldiers," while severus is translated as "stern" or "severe."