The Wailing One

The Wailing One is a creator deity in the lore of Dota 2. The Wailing Mountains may have been named after it.

According to a creation myth that the Order of the Oyo believes in, the Wailing One is a divine consciousness that was responsible for the creation of the world. The myth explains that the Wailing One was once a whole entity until it conceived a single paradoxical thought. The Wailing One could not think this thought and become one being and thus it was rent asunder, its many fragments forming the multiplanar universe of today.

Today, the various ranks of the ancient Order of the Oyo—ranging from its Aesthetes to its Brewmasters—strive to find the answer to the one paradoxical thought that the Wailing One could not answer. The one thought that would reunite the material and spiritual planes back to what it was in the beginning.

Speculation
The lore about the Wailing One sounds very similar to the lore surrounding the entity known as Zet. Although both stories have their differences, they both mention a primordial mind that predated all of existence and was subsequently shattered to witness all of creation.