Many centuries before the beginning of the RPG, The Shadow and his minion Invisible made it to Mata-Nui. Soon, The Shadow created a plan. However, he was seen by a Matoran named Proditor, and decided it would be best to silence him. He had Invisible frame him for murder.
When the RPG began, Proditor returned, and The Shadow realised he would eventually remember what happened, and had Invisible kill him.
Soon, he went to Onu-Wahi, and created a cave in which he stayed for a long time. However, a friend of Proditor's, named Pirok, discovered him.