I just want to make sure I have this time travel crap straight. Because the brown robed figure lacked a body, he was able to travel back in time to YMX and convince him to give up his body as well so that he could gather the other Xehanorts. Why did YMX need to give up his body if the robed figure already accomplished this?
Here's my concern with that. Since time travel works only one way, once Ansem SoD went back to inform YMX, he couldn't have gone forward in time again. So did he just freaking wait around for 50 something years until YMX came along to take him forward in time?