Zach is one of the main protagonists of this game. In fact he IS the player for most of the missions. The way I wrote Zach was to be in such a way that mirrors the player's experience almost. Zach is the new guy of Experimental unit 22195. His knowledge in enemy behavior makes him ideal for Field Analysis. Zach has prior training in advanced combat, but has never actually been in a battle before. 

What makes Zach unique is the fact that he knows more about the enemy more than pretty much anyone. He knows their habits, and even has his own theories on the way they strategize. His first mission will take him into one of the first alien encounters reported in the last several months. He does not believe this is a subtle attack, and thinks the enemy might be planning something big like they have in the past. He is mostly nervous sounding, however in an argument, he will make himself CRYSTAL clear on how bad things are. Very few people actually believe him with this. 

The whole concept of an on-rail arcade style first person shooter is that you have no control on where you are going. All you have is a gun, and a will to survive. This is how Zach feels, and its why this story should feel so immersive. It's because of how much the players can relate. There is no stopping what is to come, but there is a way to survive it.

If you wish to voice Zach, be prepared to have some of the most voice lines out of any character, and also be prepared for a potential sequel that you will also possibly be in.