Quick summary:
Suika-Suika intend to use all eight rooms by herself, which means no others are involved.
-Suika didn't use any of her abilities except she"not exactly" used the ability to clone herself (Apparently notimportant to the case). There won't be more of her though. <--doesn't make any sense to me.
The items-There's an item left by Suika in each of the eight rooms, these items can't all fit in a room, yet they're not physical.
-The items are some sort of tool, they're similar yet different from each other.
-They come in a set of eight and one can't be missing from the rest.
-All are common except one, but they can be found almost anywhere
-Can't be owned
What I can see from this summary is lots of unanswered questions.
Is Suika cloning something other than herself?
Did Suika know she had these "items"?
Did Suika knowingly place one item in each room?