I have seen lots of spy suggestions for a specialist but none of them really satisfied me. They all seemed gimmicky or overpowered. Here is my stab at a spy specialist.
Spy
Global: increases the radar rang of all outposts with specialists by 20%. Local: one of your opponents specialists within a spy's outpost sonar range will have a 100% chance of being in your queens next available hire (he replaces one if the specialists in the hire screen). He triggers his ability every 14 hours.
I thought this was a realy interesting and thematic idea. He can let you get certain specialists you really need at the moment. If your opponent had a sub heading tears your outpost but he also had a sabatour on his border you could move in your spy and if there are no other specialists have a 100% chance of having a sabatour in your next hire. If there are multiple specialists your odds of getting the one you want go down. Your thoughts?