war is the death of innocents. Soldiers in some ways are innocent too. Not always, but here's an example of one. Soldiers are people too. Sometimes drafted, sometimes signing up willingly, they are all in it as a job, for profit or to feed their families or whatever.
In the real world, during medieval times, raping and pillaging was part of a soldiers right as a'spoil of war'.
This guy was part of an invading force that was going to do the same to Tempest. So he had to die. plain in simple. There's no room for mercy in such things, but you still feel sorry for the guy.