Mandos is the Judge of the Dead and the Master of Doom. Originally named Námo [ˈnaːmo], but referred to more commonly as Mandos[ˈmandos].
After the halls of his dwelling. Chief advisor to Manwë and keeper of the souls of elves. He is the husband of Vairë the Weaver. Mandos is described as being stern and dispassionate and never forgetting a thing.
He was the Vala who spoke the Prophecy of the North against the Noldor leaving Aman, and who counselled that they should not be allowed to return:
The pronouncement of this Doom was the cause for the return to Eldamar of one of Fëanor's brothers, Finarfin, already reluctant to pursue Morgoth against the will of the Valar, and his people. There they asked for and received the forgiveness of the Valar.
The prophecies and judgments of Mandos, unlike Morgoth, are not cruel or vindictive by his own design. They are simply the will of Eru, and he will not speak them unless he is commanded to do so by Manwë. Only once has he been moved to pity, when Lúthien sang of the grief she and her lover Beren had experienced in Beleriand.