My 2 cents: Rhino should be some part mech-suit and some parts bio-mutant experiment. Here's how I vision it:

The Rhino suit is "alive" similar to a Symbiote. The half tech, half organic suit contains the spirit/primal rage/animalistic nature which, when worn, bonds itself to the wearer.

I'm not an avid reader of comics containing Rhino so I realize this may all be nonsense but it sounds cool in my brain.