My opponent attacks with AUTO and draws 2, but does not exchange.  I block with The Judean Mediums and band to Trembling Demon.  If my opponent discards a good enhancement from hand, is Trembling Demon negated?  Based on his ability's wording, I would say "No".  
The Judean Mediums - "If blocking and opponent has used a draw or search ability this turn, demons and magicians cannot be negated.  May band to a demon or magician."
Trembling Demon - "If no good Enhancements are played this battle, protect all Lost Souls from rescue. Opponent may discard a good Enhancement from hand to negate this."