Armor — John Steakley

UNIVERSAL SOLDIER
The planet is called Banshee. The air is unbreathable, the water poisonous. It is the home of the most implacable enemies that humanity, in all its interstellar expansion, has ever encountered.

Body armor has been devised for the commando forces that are to be dropped on Banshee--the culmination of ten thousand years of the armorers' craft. A trooper in this armor is a one-man, atomic-powered battle fortress--but he will have to fight a nearly endless horde of berserk, hard-shelled monsters--the fighting arm of a species which uses biological technology to design perfect, mindless, war minions.

Felix is a scout in A-team Two. Highly competent, he is the sole survivor of mission after mission. Yet he is a man consumed by fear and hatred. And he is protected, not by his custom-fitted body armor, but by an odd being which seems to live within him, a cold killing machine he calls "The Engine."

This is Felix's story--a story of the horror, the courage, and the aftermath of combat, and the story, too, of how strength of spirit can be the greatest armor of all.