When King Randor was injured during an attack by Beast man & the Shadow Beasts, young Prince Adam used his mastery of Eternity to slow time so that Lt. Daegar & Mendor were able to arrive in time to save the king.
Mendor is the royal physician who delivered Adam into Eternia. Mendor healed Teela's leg after the initial assault on Eternia by the Horde. After the Goddess commanded the snake men to serve He-Man, Mendor healed Rattlor. Rattlor was grateful as King Hiss would have let him die.
Mendor uses his mastery of healing magic to save injured warriors & citizens of Eternia.