The mark of any good villain is their motivation for why they do what they do. Their 'bad guy' label so often rests on their actions, rather than their intent, and while the actions of a character can be misinterpreted, their motivation for doing so is rarely misunderstood.
Presenting the player with reasonable steps that paved the way for a villainous decline tests their own moral compass, which creates an interesting discussion around the justification for the antagonist's actions.
The hero of the story may be shrouded in blissful ignorance to the true motivations of the antagonist, or they may simply disagree with their motivation all together, but inserting an intriguing motivation into the make-up of a villain undoubtedly serves to elevate the overall quality of any video game story, as well as the villain's character. Without Bowser's constant kidnapping of Princess Peach, Mario's heroics are futile, and providing the villain with a great motivation brings legitimacy to why the battle between good and evil exists.
Not every game achieves such a feat. Providing an effective motivation for villainous deeds is tricky, but these ten games manage to get it right.
10. Katherine Marlowe - Uncharted 3
Despite Uncharted perhaps being the pinnacle of linear storytelling and character development, the villains in each entry are almost always underwhelming.
Roman was a generic, pompous rich guy and Lazarevic nothing more than a brutish, cliche Eastern-European warlord. Uncharted 3's villainous duo, Katherine Marlowe and Talbot, attempted to break the mould of mediocrity, and though their presence is never the focal point of the tale, they did a rather good job.
Katherine Marlowe is the leader of a centuries-old order created by Queen Elizabeth I, a secret society dedicated to the preservation and continuation of Britain's global influence and power. Her obsession with legendary explorer Sir Francis Drake and his voyage to Arabia are fuelled by her stubborn commitment to crown and country, and a young Nathan Drake was a pesky thorn in her side.
Katherine Marlowe's motivations are driven by fulfilling British conquest which the order has fought centuries for. So few stories on the medium use British history to motivate a villain, which adds an interesting wrinkle to Marlowe's threatening presence.