It's kill or be killed in the megastructure, no surprise there.
We learned a tiny bit about Killy's origin, he has apparently no registration code or rather, he had one but it has been erased, probably by his employers considering that he is a special agent on a mission to find net terminal genes.
The GBE is class 1 critical effect weapon, I guess there is nothing superior to it.
The elevator dude was a safeguard I guess, he didn't stand a chance against Killy who doesn't even his gun.
Speaking of the GBE, holy crap, you have to love that thing, 70km long holes without even using full power. Let's hope Killy finds Dhomochevsky soon and takes his gun back or else he is in deep shit when Schiff shows up.