Survivors of Hell PBP combat simulator

[customizing till the end]

Record the encounters from this thread
http://paizo.com/threads/rzs2t843?Survivors-of-Hell

[Snowlilly]

Wave 1

• 1 Nupperibo Devil (1HD)
  
• 1 Nupperibo Devil + 1 Lemur (3HD)
  
• 2 Nupperibo Devils + 2 Imps (8HD)

[customizing till the end]

If nuperribo devils were being picked off, the Hells would send someone else. How do you handle invisible imps?