From Halopedia, the Halo wiki
Sangheili Minors are logically, physically, and pragmatically the least-experienced warriors of their race; however, they are still skilled in combat. They are somewhat weaker than their crimson-armored Major superiors and occasionally will perform unwise tactical mistakes, such as standing in an ally's line of fire, or taking long pauses to roar at their enemy before attacking. Being the lowest ranked in the Sangheili military hierarchy, they possess energy shielding that is weaker than any other Sangheili, (besides that of stealth units), and is also inferior to the shielding of MJOLNIR armor.
Although the lowest and most common of the Sangheili ranks, the Sangheili Minor's threat is not to be underestimated. Most Sangheili in this class can still easily overpower a human. Known primarily by their iconic blue armor, Minors who show leadership initiative are usually deployed in small strike lances or in leadership roles above Unggoy and Kig-Yar squads, while those Minors who exhibit more bravery than skill will instead report to a Sangheili Major or Officer. If the Minor leading the lance is killed, their subordinates will often flee. Minors who are neither promoted nor killed during their first campaign typically commit suicide to retain their honor.  [Note 1]
Following the Human-Covenant War, the rank of Minor continued to be used in Merg Vol's Covenant. Many Sangheili of this rank fought on behalf of the group during the Battle of Draetheus V in 2554. While Jul 'Mdama's Covenant use Sangheili Storm in place of Minors during most battles, the rank has seen use at least once by the group.
Sangheili Minors wear distinctive cobalt-colored combat harnesses in Halo: Combat Evolved. In Combat Evolved, there are two differently shaped variations of the helmet. The more basic helmet features fins on the sides and rear. The secondary helmet from Combat Evolved is more curved toward the back.
The color scheme of Minors' armor was changed to sky blue in Halo 2 and featured two shades of blue in Halo 3. The Sangheili's armor in Halo 3 was also more detailed, featuring Forerunner glyphs on the armor and a design with many armor seams and sharper angles, creating a more technologically advanced, alien look. In Halo: Reach and Halo Wars the design of the harness is more akin to the design in Combat Evolved, having the armor be shinier and curved, simpler, and with a smaller helmet with no mandible guards, creating a more combat orientated look.
Minor are the most commonly seen in Halo: Combat Evolved, Halo 2 and Halo: Reach on the Easy and Normal difficulties. On Legendary and Heroic, almost none are present. In Halo 3, the only level Minors appear in is The Covenant. Sangheili Minors are usually found leading lances of Unggoy, but they themselves will likely be led by a Sangheili Major.
Their armor's energy shielding is weak compared with that of higher-ranking Sangheili. Showing off at least some sign of intelligence despite their inexperience, Minor Sangheili are capable of hiding when their shields are lowered and will attempt to attack anyone foolish enough to enter into close combat with them with their weapon. They often make tactical errors such as standing in the way of an ally's fire, rushing forward into enemy fire and forgetting to take cover which leads to a lot of deaths (even at the hands of a UNSC Marine). They will seek less cover, often standing in one spot to fire and strafe less often than their superiors. When they are seriously injured or unshielded, they will also go "berserk", yelling a war cry and attempting to melee their opponent to death. They also fire in shorter bursts, and have somewhat less accuracy and lower rate of fire. Still, one should not underestimate them, especially on the Heroic and Legendary difficulty settings.
Minors usually wield plasma rifles, occasionally dual wielding them. Most of the time, Minors will not carry weaponry as powerful as a higher-ranking Sangheili. Occasionally, Minors may also wield energy swords; whereas Sangheili who do not hold the title of aristocrat are not permitted to wield swords outside the battlefield, this policy does not apply in the military.
List of appearances