Website and data research by 101Leafy.
Death Emblem
デスエンブレム · Key item
Ranks up a certain demon
Versions: Aka no Sho, Kuro no Sho
No shop sells it, no chest holds it, no enemy drops it, and 101Leafy has not found a story event that gives it.
Shin Megami Tensei Wiki by 101LeafyAll Demons Index