Forgive what may be my possible ignorance, but what I think he actually means is:

1) Spawn enemy actor equipped with some sort of attractor weapon. Particles have negative mass, etc.
2) Enemy actor proceeds to fire at you, pulling you toward them.
3) Enemy actor, who has a limited lifetime, disappears.

I would be greatly amused if, when this sort of device could be made to work, the enemy was represented by a blue portal (from Portal) and the shell was the orange portal.

Huh. Another idea strikes me, but it would only work if actors loaded into rockets/dropships could also be unloaded again. Can they?

(Hopefully this first post doesn't fail)

If they could, we would have made your idea by now.
Sorry.

I know how to make a-

Hold on..

*mods*

General requesting read PL0X?