Half-brother to King Randor, exiled prince of the House of Miro. The 2002 MYP continuity establishes him as Skeletor's pre-curse identity, transformed when a vial of acid destroyed his face during a confrontation with Captain Randor.
Keldor is the 2002 MYP continuity’s answer to “where did Skeletor come from”: a half-brother to King Randor, exiled from the royal court, whose face was destroyed in a confrontation with Randor’s Captain. Hordak saved his life by binding a demon to his exposed skull, completing the transformation into Skeletor.
The Keldor backstory has been retained across every later continuity. The 2021 Revelation continuation visualizes Keldor in flashback. The Revolution sequel makes explicit Skeletor’s confrontation with his pre-curse identity. Mattel’s Origins line has released a vintage-style Keldor figure that lets the character exist visually as both the Keldor-form and the Skeletor-form on a collector’s shelf.
Catalogue source: heman.fandom.com (CC BY-SA 3.0).