It was created by the Gods so that it can manage the world in its place. Aeons passed and some of the Gods became corrupt, trying to interfere with worldly affairs so that they can collect mana. In the process, the System gained sentience and noticed their tampering so consequently, it took matters in its own hands. It materialised itself as the World Tree, basing itself as the centre of all mana so that it can condense power. Mana is the energy of the universe and even Gods, without enough mana, cannot sustain themselves. While doing all of this, the elves flocked to the World Tree and formed the Elven Epoch, essentially worshipping the World Tree as a God. It is not known that the World Tree is the manifestation of the System.