Spoiler

 

I think it is been revealed what is in the black I got a few theories:

1. Xigbar has summoned them that is also probably why Pete&Malifecent were dissapointed to see what is in the black box.
2. It is possible that this is a time machine that could be a reason how Maleficent travelled through time
3. Since Ava didn't make it it is possible that just the soul of MoM is in the box.

I personally think that it are those foretellers who are in the box and mayby MoM who will be revealed later.

 

 

Spoiler

I like the second Idea the best we see in the fight against young xehanort in DDD that he is using some kind of machine aswell and if he had been always capable to go back in time whenever he wants he could have got himself a lot more backup darknesses so my guess is there is a time limit on this time machine and somehow it got lost or stolen or what not which has to be explained later

 

Hasn’t she been able to travel through time the whole time?  What about that Timeless River stunt?

8 hours ago, VisitJoan said:

Hasn’t she been able to travel through time the whole time?  What about that Timeless River stunt?

This is different they are travelling through dimensions.

8 hours ago, VisitJoan said:

Hasn’t she been able to travel through time the whole time?  What about that Timeless River stunt?

that seemed to be something to do with pete

On 2/10/2019 at 2:23 AM, VisitJoan said:

Hasn’t she been able to travel through time the whole time?  What about that Timeless River stunt?

That is because of the cornerstone. They have been able to travel and there. As if that was a point carved into the past of the Disney Castle, which made it so relevant.