genii (n.)

late 14c., "tutelary or moral spirit" who guides and governs an individual through life, from Latin genius "guardian deity or spirit which watches over each person from birth; spirit, incarnation; wit, talent;" also "prophetic skill; the male spirit of a gens," originally "generative power" (or "inborn nature"), from PIE *gen(e)-yo-, from root *gene- "give birth, beget," with derivatives referring to procreation and familial and tribal groups.

The sense of "characteristic disposition" of a person is from 1580s. The meaning "person of natural intelligence or talent" and that of "exalted natural mental ability, skill in the synthesis of knowledge derived from perception" are attested by 1640s.