Octillery would not be blocked by Magic Bounce because it can get rid of Magic Bounce with Entrainment before using Soak.
You are mistaken here, Entrainment is reflected by Magic Bounce. If Octillery uses Entrainment on Espeon or any other Magic Bounce 'mon, Magic Bounce will trigger, make Espeon perform Entrainment, and give Octillery Magic Bounce. This happens with all moves that can be used to remove an opponents ability, like Worry Seed, Gastro Acid or Simple Beam. The only exception appears to be Skill Swap (which would anyway work the same if it gets bounced).
Not that it matters, since Multitype stops everything including Skill Swap, anyway.