interesting , but while the idea of the greatgoblin cant leave the base and be base protecter is very good , but i think he will be useless , just bring some catapults or lorien archers with there long range , they will force you to get out of the base , its no use , however i have nothing against the rest of your ideas , and it will be very funny and unique at the same time if the greatgoblin have an ability to inslave enemy troops instead of killing them then they will enter the tunnels and work lol