Seventh Founder
The countercultural Necromancers worshipped an incomprehensible "seventh Founders of Gallifrey", whom they referred to as "the other". who was nameless, genderless, and historyless. It was unclear whether this "other" was the same as the Other that was part of the Triumvirate, although their labelling as "seventh" (contrasted against the usual count of six) implies a separate identity to the member of the Triumvirate. (PROSE: And To Dust We Shall Return, The Book of the War)
In imitation of this "old one", the Nechromancers renounced their identities, expunging their names and genders from House records to embrace their otherness, and flat-out refused to believe that time existed as such. (PROSE: And To Dust We Shall Return)