The ego-destructive superego names that configuration of internal agency in which the superego — rather than guiding, restraining, or integrating the ego — turns against it with a ferocity that threatens psychic annihilation. The concept travels across several generations and schools of depth psychology, each lending it a different etiological weight. Freud identified the superego’s sadism against the ego in his accounts of melancholia and the death instinct, proposing in 1923 and 1924 that the superego could function as a conduit for thanatic energy directed inward. Melanie Klein dramatically radicalized the picture: her pre-Oedipal superego, formed under the dominance of paranoid-schizoid splitting and projective identification, is constitutively savage, a terrifying persecutory object that pre-dates conscience proper. Edmund Bergler, as elaborated by Kalsched, pushed this further still, arguing that the sadistic superego — a ‘daimonic’ internal monster — constitutes the core of all neurosis, not a derivative complication. Karen Horney, approaching from a different angle, disputed the instinctual grounding of self-destructiveness while acknowledging the tyrannical inner demands that parallel superego sadism. Kalsched’s own contribution reframes the ego-destructive superego within trauma theory, linking it to the self-care system and archetypal defences that paradoxically become the instruments of the ego’s persecution. The tensions among these positions — instinctual versus relational origin, structural versus phenomenological description, pathological versus normative range — constitute the living theoretical problem.