...?

Maybe they just left this particular area of the ship and you haven't actually bothered with looking around?

The Bronze Elder Soul: Maybe they thought-wrongly-they could survive the time-space barrier?

Scyez: It's OK everyone! I took their blankets!

*Holds up the 'blankets,' AKA cloaks, of Nightmare and Dark Mind. How in HELL she got those...Let's just not think about it too hard, she probably ripped them off directly without any idea how strongly they're connected to their owners whatsoever, which probably worked to make them removable in the first place. She's too ignorant to know they could possibly teleport back to their owners or regenerate, which subsequently would have prevented those safeguards from working. Yeah, Ignorance works like that...Unfortunately, neither Dark Mind nor Nightmare could come aboard now if they left prior to the breach. You're nowhere to be found in the super-dimension you've left behind, so if they're aboard, they probably will come for their clothing.*