i'm making a hellboy II mod

I am in the process of making a some modded characters based on creatures from the movie hellboy: the golden army and of course I wanted to include the golden army as a unit (which you would only get to use once). Anyway in the movie the golden army is indestructible and i was wondering if there was a way to make a unit indestructible. basically the project is a short campaign in which you fight to control the golden army then get to use it very near the end. Is there a way to make a unit that is invulnerable other than simply giving it massive health and armor since this would be obvious in the unit stats. the whole things is a sort of a tribute so i wanted to keep somewhat in the spirit of the movie. I considered trying to make a unit that could respawn in battle but that would be too much for me as the changes necessary would be very difficult and probably it seems impossible. anyway if someone could help me it would be much appreciated.