There's a big plothole explaining Ansem gaining ability to traverse back in time, or is that explained in the YMX reports?

There are no reports in this game. What is the plothole?

Kingdom Hearts 3D-related topics belong in the Kingdom Hearts 3D section... obviously.

Could you please explain this plot hole? Because concerning Ansem's ability to travel through time; there isn't one.

if you would at least tell the "plot-hole"

like all other said. It was mentioned that in order to time travel, y need to cast away yr flesh and become just a heart. In Ansems case he had no flesh and he was already Xehanorts heart.

I think he's referring to previous time travel concerning the Timeless River. I think it's to be assumed (at least by a member of KHInsider) that Xehanort and Merlin just use different methods and that Xehanort's is just the long way while Merlin's is merely magic of a powerful wizard.