What a BHoC really is...

Everyone can probably guess that RedWolf's Black Hole of Calcutta (BHoC) isn't a real black hole, although it expells similar radiation.

The question is... what really is it?  I don't have any ideas myself, and Aticston was wondering hirself.

Requirements would be:

• Be a mass store (or well), with the side-effect of converting it slowly into energy.
• Allow mass to be moved to/from the 'shifter's body with decent speed (aka shifting in under a minute), even if it is self-powered.
  

Now, granted, we will be employing pocket dimentions; this is a given with Dryger technology.  Could this be more Dryger tech?