Yea Oner would be the one to do that. Reno would paint a simple picture that would make things even more complicated than they really are with an explanation that would take a very long time to decipher XD
Except Oner. But by the time that would happen it would be a whole lot easier if Oner explains the thing himself XD
And yea, a good time to ask Reno/Oner though (in my own personal opinion) could be after Joshua sees Reno use Dark Megaflare (but again, ill leave when you want to have Joshua actually ask this question up to you ^^)
Quite some time. I had already beaten the game, and every other boss in the game (even Xemnas) and leveled up to 100. I died twice but the third time I finally claimed victory.
Why not have Ascot spot Amaya approaching and go talk to her. He would probably be surprised Joshua aint near her, given how they've pretty much always been together