Alter Ego

Alter Ego (アルターエゴ) are beings created by BB as a Heroic Spirit-Complex.

Nature
Classified as a High-Servant (ハイ・サーヴァント), she was created from BB accessing the Moon Cell's Servant Archive and selecting goddesses compatible with Ego from inside of it. They were five alter egos of BB, formed by five emotions: love and hate, joy and happiness, purity and chastity, compassion and affection, as well as lust and yearning. The Alter Egos symbolized the sensuous parts of the female body. Passionlip represented the breast, Meltlilith the feet. The other Alter Egos represented eyes, lips, and back.

Alter Ego were born with special skills called "id_es". They were the results of illegal modification. Id_es were the morphing/reinforcement of the Alter Egos' existing abilities. Most of them were skills that normal Servants did not possess. They were the exposure of an individual's psyche, rather than the abilities of the corpus. Besides Passionlip's Masochistic Predisposition, Meltlilith's Sadistic Predispostion, there seemed to be other types of ide_es, including Infantile Regression, Bondage Paraphilia, and Cognate Aversion.

Sakura Five
In the early design of CCC, the boss of Level 1 was Red Lancer. The bosses of Level 2-6 were the Sakura Five. BB or the Mastermind would reside on Level 7.