Hmm...
How about this. The Human more Living. For example simulate him going through cold or Hot areas. Cold will weaken the immune System while heat will weaken the virus thingys. Of cause you can't make him move so uhm do it with text.
I would like to see something like a Injection. Lets say that Human just went to the doc and got some medicine their. The Location for the Injection would be pinged then some unit (simulating the needle flies in) and spawns some anti... uehm thingys. With a chance of like 10% the injection is contaminated with a Virus.
|