How does Pandamonium work with effects that destroy unicorns?
You don't have any unicorns in your stable

Pandemonium turns all of your unicorns into pandas for all other effects.  This means that any effect that does something to the unicorns in your stable will see that you have zero unicorns and act accordingly. 

This can be a pretty powerful protective shield at times.  The catch is that you can't win the game while it's there.