I once read a series of books that I'd really like to find again. It was sci-fi based. One man is the last of his race (they were a warrior race that lived on a planet and were hired out as mercenaries in war, and fearing this, an unknown enemy unleashed a virus/disease that killed everyone except this guy, who was saved by some doctor dude). It has aliens and fights and star travel, and that's about all I remember. This guy is an uber-warrior and defeats a lot of people. One of his companions is some female alien. I don't know the name of the author or any characters, but this has been plaguing my mind for a while now. I remember that at the end the main bad guy was this big tentacle thingy/mastermind. I know this is all very vague but I'm desperate!