[DarkSkiper]

Spoiler for crazy idea:

Oh by the way, now that I think about it what if the memory world where Saten and Yamada were, was created by Yamadas fragment?
It's like the shard hit Yamada the shock made his power surface and because what he saw was Blade memory and an illusionary world was created and so Yamada along with Saten for the ride were trow in there?
It might explain how Yamada edited it and removed the darkness.