click on the image that says dark soilder.
look at the bottom right photo. that clip was not in the kh2fm+ secret ending, i zoomed in to the photo and the head looks like young xehanort. it's not dark soilder, because the skirt thing is too long.
Phoenixblade804 - Photobucket - Video and Image Hosting
this could be young xehanort in birth by sleep.