I really like this description of Locke.
Locke is meant to be variable and multi-faceted. We’re all different people at different times, and while there are some very strong and attractive aspects to his character, he also has some pretty serious weaknesses. He is charming, loyal, and lovable, and energetic and clever and highly sensitive to the nuances of the people around him. He’s also self-pitying, morally weak, careless, and stubborn to the point that he’s a danger to himself and others. Locke is uniquely skilled at contorting and talking his way out of risky situations, but the fact is he might not find himself in those situations if he’d only think things through more broadly and carefully to begin with.
Locke has a powerful conscience, but it’s not a steady and reliable guide to him… it’s more of guilty self-rebuke that emerges when he starts to go too far. He’s a crook through and through, a socialized crook who has more of a super-ego than most of his kind on account of Father Chains’ intervention in his life. He’s still capable of supreme ruthlessness and murder, and of unjustifiably hurting innocent bystanders in his quests for vengeance.
I think, if I do my job properly, you should like him… and then occasionally loathe him… and then cheer for him… and then want to slap some sense into him. Sure, he’s a hero, a man of great skill and capacity whose deeds greatly influence his world (both visibly and invisibly), but he’s not meant to be one note played over and over.