The Wise One was initially a human. Or at least, not the floating rock it looks like. It ended up being whatever became of the recipient of the last Golden Sun Event's power. It gained the psynergy of all the elements, changing it in such a way that it could no longer be called human. This change also allowed it to see the future, and live for eons. It knew that Isaac would come along and be the key to releasing psynergy, so it kept the stars safe for that time. When Isaac's Golden Sun rose, the Wise One prepared for Alex's treachery and had already imbued the Mars star with part of its power. When Mt Aleph sank, the Wise One exhausted the remains of its power- a power that was linked with the Golden Sun. Not only did the Wise One expend massive amounts of Psynergy sinking the mountain, but it was also leeching into Alex and Isaac both. Psynergy follows the laws that energy does in this world: it is neither created nor destroyed. Instead it is shared, spread throughout all. When Aleph sank, and the Golden Sun rose, the Wise One exhausted its power, and became the dust it should have been eons ago.