When was the XIII Organization founded?
The timing is when Philosopher Ansem's 6 disciples turned into Heartless. The XIII Organization is called like that just because it has recruited 13 members, but it doesn't matter if it has "XIII" in its name or not. All 13 members were already gathered in KH:COM but the members that were in Castle Oblivion still called it as the "Organization."
Okay..this had to have happened before Sora obtained his keyblade. For Ansem(Xehanort's Heartless) had such vast knowledge of Heartless and the Darkness and the connection of the worlds (which I assume would take some time) soon before Sora got the keyblade. This is not fact..just my speculation...
Anyways, Zigbar told meantioned to Sora about "others". Nomura himself hints about these "others" to be past keyblade weilders. Also, if im not mistaken, Xigbar called Sora weaker than these "others".
My question is, where are they? How does Xigbar know them?
Currently Sora and co. are the only Keyblade wielders and they're doing things that grant them the titles "Heroes of Light" but, as stated in the first game's Ansem Report #8 and the secret movie this time, the real Keyblade wielders "can bring chaos to the world, just as one can bring peace to it."
Certainly Xigbar didn't defeat them, for he couldn't defeat Sora who was "weaker" than them.
Im not looking for an answer...just for your speculation and ideas.