Maleldil is the Celestial Emperor, the constitutional monarch of the Upper Planes and commander-in-chief of its armies. He was elected to his position to watch over the multiverse and ensure that all life is given a chance to evolve and ascend to the Upper Planes. During his reign, he established the Elder Council, a group of beings devoted to protecting innocent sentient beings from destructive forces such as the Great Old Ones or the agents of the Archdevils.
It is said that Maleldil was first of the original generation of Elder Gods to come into existence many billions of years ago. He developed a strong sense of peace and justice that became useful when monitoring sapient beings. When the war with the followers of Azathoth began, he was put in charge of the Celestial army. Maleldil fought hard, but he always gave his enemies a chance to surrender and would not kill beings from Azathoth's realm if they posed no threat.
When the first devils, led by Asmodeus, declared war against the rulers of the Upper Planes, Maleldil and his loyal soldiers fought back. Although this was the first time that Elder Gods fought against each other, Maleldil followed the same rules as when dealing with the Great Old Ones. The war caused much damage to the Upper Planes, but Maleldil was victorious. Once Asmodeus was captured, Maleldil sentenced him and the rest of the rebels to the hell planes.
Not longer after Maleldil won the war, the Celestial Parliament nearly unanimously elected him Emperor of the Upper Planes. He was given the authority to enforce the laws of Heaven and protect the evolution of all sapient beings. Although his political authority does not extend to the material planes, he is still worshipped as a deity on several worlds.
When he discovered that the Archdevils were still able to influence events in the material planes, Maleldil was honor-bound by the Pax Primeval not to invade the hell planes directly. Instead, he created the the Elder Council as a group of gods and ascended spirits that would seek those who could protect the weak and innocent from those who served malevolent beings. Although Maleldil has occasionally made decisions with negative consequences, he continues to be the most trusted voice on the council.
Maleldil has been known to occasionally visit worlds that have fallen to the influence to the Archdevils, including Megacrossover Earth, and implant portions of his spirit into the bodies of newborn children. Those that carry a piece of Maleldil's spirit tend to become great religious leaders and philosophers.