In my new military horror campaign, one of the main story arcs will involve an alien nano-virus that infects humans. I want to stat out what happens to those infected.
Basically, there are two levels of infection - the controller and "minion". The controller retains its ability to think and speak and it can control any minions in close proximity (think like a hivemind).
The minion is virtually mindless. It is merely a pawn of its controller. It can perform simple tasks (guard, carry, attack, pull trigger) but not much more. It does have increased physical abilities but is immune to any kind of mental manipulation, fear, coercion, etc.
If the controller is killed and the link broken, the minions become mindless killers. They lose any ability to think or problem solve. They are not undead but essentially "forget" to eat or sleep and completely ignore pain. Their controller essentially keeps them "alive" because once the link is broken, they lose any ability to nourish themselves.
I'd like to give them some kind of "berserker" ability once the link is broken as well as something that emulates their savagery when attacking since they don't use weapons. Even though they are mindless, I don't really think the construct quality applies.