The Mass Effect universe is packed full of lovable characters that players will get to learn more about during their galactic adventures, but it also has its fair share of monstrous individuals who are as ruthless as they are intimidating. While the main threat of most of the games is the Reapers and their inevitable invasion, each entry still contains more than a few despicable characters who, for one reason or another, are opposed to Shephard and his crew, usually for their own selfish gain.