AAauuh, well, this is all the work of the temple itself, admittedly--as soon as you leave this room, those bandages will vanish, so again, this is just until I find one of those with a healing ability! [Ahahaha...anyway.]

That said, since this has also robbed you of the chance to receive an explanation by touching the 'Heart', I, the man Gongenzaka will explain.

The gem here brings others from various worlds, changing them into 'gems', [He gestures to his hematite] for the purposes of facing off the creatures which reside here as well. As of yet, that is the most we know in terms of 'why', however...that and the fact that we cannot return home willingly either.