Metatron appears only in the updated Shin Megami Tensei III: Nocturne, titled Shin Megami Tensei III: Nocturne Maniax. Should the Hito-Shura accepts the old gentleman's request of retrieving all the Candelabrum that have been stolen, Metatron will intervene the Hito-Shura, warning him not to meet with the old gentleman or continuing venturing the Labyrinth of Amara, or he shall suffer the wrath of the Absolute One.
Should the Hito-Shura chooses to ignore Metatron's warnings, Metatron will stand in the Hito-Shura's path, forbidding him to meet up with Lucifer. Metatron the Hito-Shura for disregarding his warnings, enraged, he attacks the Hito-Shura, hopping kill the Hito-Shura before he threw away his last vestiges of humanity. After Metatron is defeated, the Hito-Shura can summon him in the Heretic Mansion. Metatron can only be summoned by fusing Michael and any other Divine or Seraph race. Subsequently, a Tyrant race demon is needed to sacrifice in order to summon Metatron.
Persona 3
Metatron is the Persona of the Sun Arcana. He can be summoned once players reached Lv 78 or higher. Metatron's fusion prerequisite requires Michael, Gabriel, Raphael, and Uriel to perform a cross-spread in the Velvet Room.
Persona 3: FES
In the updated re-release of Persona 3]], titled Persona 3: FES, Metatron's arcana was changed to the Aeon arcana, and represents to final arcana of the Aeon. To summon Metatron, the Protagonist must max-out his Aeon Social Link. By finishing the Social Link, Aegis will present the Protagonist her charred screw, bestowing the accessibility of Metatron.
Metatron is the voice of God. When ever someone says God spoke to them it's actually Metatron. He has one million eyes and mouths all over his body, and every mouth speaks a different languge. The seraph who is the nearest one of Y.H.V.H.. He has the largest body among all the angels with 36 wings. In Judaism, his status is even higher than archangel Michael. He received various titles such as "Face of God", "Angel of Contract", "King of Angels", etc.
However, Metatron isn't an official Christian angel. His name has never been mentioned in the Bible. His celebrity is no compare with Michael. Metatron turns out to be the most mysterious.