how do i make the computer fight back?

Maybe you can use gravlifts that push up the fusion coils to the mancannons and then you gotta kill the grav lifts.

 

does it have to be automatic, or can players help out

 

Usually people make objectls fly and hit you, you could do that.

 

I just said USE GRAVITY LIFTS. Make 2 or 3 chambers and at the bottom have gravity lifts and random objects will then spawn. The gravity lifts will push up the objects into the mancannons shooting them at 'his' opponents. Make it so the players can see the gravity lifts and be able to shoot them.
Then have territories in the chambers where the gravity lifts and so you will have to kill the grav lifts to take over the territories.

 

Put barriers in front of the grav lifts.

 

Hmm, I guess what jpitty says could do, but I don't think there's any other possibility.
maybe you could do the timed map events technique, like let things spawn out his hands or something. And I tihnk Fusion Coils are a bit unoriginal.

 

make it out of distructable items like crates and have something like fusion coils as joints so you can shoot them and make it fall down.

 

Elaborate on how that is impossible.

 

Make a small slot with a teleporter arrow pointing at it where you have to throw a nade to blow up whatever is powering the boss/robot (fusion coils/gravlift/etc).

If the slot is small enough and in an awkward location, it may be hard for the player to throw the nade inside without getting blown up by whatever the boss is using for attack (fusion coils/crates/etc).

 

with what jpitty said except put a territory in it and you have to kill the grav lifts that throw the fusion coils and have teleporters that the grav lifts throw you into
So when you kill the grav lifts you can walk trough the hallway that the grav lifts are in like this
----l**l---l**l---l**l---l**l----
____^____^___^____^____()

()= territory
l**l = death teleporter
^ = grav lift