U-Mos

U-Mos is the current Sentinel of the Luminoth, born to the third sentinel, V-Mos. When the Ing conquered much of Aether, he ordered all the surviving Luminoth into the Great Temple to enter cryogenic hibernation, and awaited the end. Samus stopped the siege on the Great Temple, and accepted U-Mos's plea for help to restore the Light of Aether.

U-Mos is the son of V-Mos, who was another Sentinel of the Luminoth. He is 2.15 centicycles old (the oldest Luminoth lived to be 1000, which would make U-Mos in his 20s by human standards), intelligent, brave, and honorable. However, like most of Samus's allies in the Metroid series, U-Mos guides Samus to her destinations without actually going with her; U-Mos must stay behind to protect the cryo-chambers of his sleeping brethren. It is possible that U-Mos is one of the most powerful characters in a Metroid game: if Samus tries to attack U-Mos, he brings up a psychic force field which deflects every weapon in Samus's arsenal, and he also has telekinesis and can fly. He can produce holograms from his hands using his psychic abilities, a power that all sentinels share. His offensive capabilities are unknown, but it is known that the Luminoth's ability to generate and manipulate energy is on par with the Chozo, which suggests he is formidable in combat. Also, he was able to protect the Great Temple and sleeping Luminoth for a presumably large amount of time until Samus's arrival on his own, showing that he probably has enough power to fight off the legions of the Ing single-handed, although he probably cannot launch any major offensives against them even with his powers, since he had to wait until Samus arrived to restore the Light of Aether.

Logbook entry
Metroid Prime 2: Echoes: Subject is U-Mos, a Sentinel of the Luminoth. Scans indicate numerous beneficial abilities, including heightened reflexes, durability, psionics, and flight. Ability to generate and manipulate energy on par with that of the Chozo. Dating scans suggest an age of 2.15 centicycles. Only known active member of the species; remaining Luminoth locked in protective stasis until crisis is resolved.