There are few characters that Chosen Undead revile as much as Knight Lautrec of Carim from Dark Souls. After rescuing him from his prison cell in the Undead Parish, one would expect him to be an ally or a merchant. Instead, he turns out to be a murderer and thief who the player has to track all to way to Anor Londo in order to retrieve the soul of Anastacia, Firelink Shrine's firekeeper.
His motives are never fully explained, but from his dialogue and some item descriptions, gamers can discover a bit more about the enigmatic Embraced.
10 He Doesn't Need The Player's Help To Escape His Cell
It is not uncommon for players to use the mystery key to unlock his cell in the Undead Parish. Either to follow his quest and obtain his armor or to slay him immediately for the powerful Ring of Favor and Protection. Plus a few humanities. But this part of the quest is seemingly unnecessary. After defeating the Bell Gargoyles he will somehow escape his imprisonment and end up at Firelink Shrine. Where he will watch and wait, observing his prey before striking.
9 He's Weak Against Kicks
Even though his armor and fighting style doesn't offer a tremendous deal of defense against most kinds of damage, there is an even easier way to kill him. From where he is seated at Firelink Shrine, players can kick him once to get him to stand up and to become vulnerable to further harassment. With a second well-placed kick, one could send him flying off the ledge and into the deep canyon beyond. Simply reload the game and his drops will be near the ledge, ripe for the taking. Also, Anastacia will now be safe, with her would-be murderer dealt with.
8 Literally Embraced
It can be quite hard to tell from a distance, but his armor has two arm-like patterns across the front, making it look as if he is being embraced. This is very symbolic and represents his connection to divinity. It seems like an odd addition to a piece of armor and likely has no function. At least, none that the player can glean. Though the description of this chest piece mentions that these might very well be the arms of the goddess Fina.
7 Devoted To A Deity
Much of the item descriptions tied to Knight Lautrec and his story mention the goddess Fina. She makes no significant appearance, besides being mentioned briefly and having a statue here and there.
All the Chosen Undead can learn about her is that she has a fateful beauty and that Lautrec loved her. Furthermore, she possibly loved him in return.
6 Token Of Love
On the Ring of Favor and Protection that Lautrec drops, the description mentions that it symbolizes the favor and protection of the goddess Fina. In combination with Lautrec's armor description and visual aesthetic, it can be theorized that Lautrec indeed was loved in return by Fina. That is unless he stole these items instead of having them bestowed upon him, not unlike how he steals Anastacia's soul.
5 Reason For Imprisonment
Back when the player first finds him in the Undead Parish's suspiciously solitary prison cell, he appears to simply be sitting there, resigned to his fate. As calm as one could be. Initially, this isn't very odd compared to other things experienced so far by the Chosen Undead. That is until one begins to consider why a parish needs a prison cell and why Lautrec is in it. Also, why the knight is imprisoned so close to the most significant statue of Fina in the entire game. He is known as The Guilty because he murders Anastacia later on, but it is also possible that this is not where his guilt began. Maybe he committed a grave sin against the gods, particularly one goddess.
4 Not The Only Guilty One
Lautrec's guilt may be known far and wide, but he is not the only one who has sinned. Sin is an integral part of covenant mechanics but doesn't affect single-player gameplay too heavily. Though, in lore, it represents deeds done, or spoken, against the gods.
Through dialogue with the Crestfallen Warrior, it can be learned that Anastacia doesn't speak to the player due to having had her tongue removed long ago. He also hints that the reason may be due to something blasphemous she said. Considering this, and that Lautrec spends quite a bit of time close to where the firekeeper is imprisoned, it is doubtful he targets her randomly.
3 Retribution For An Insult
If one believes the theory that Lautrec goes about his actions for the goddess he loves, another theory could come forth. It is mentioned that Anastacia once said something horrible enough to have her tongue removed and be imprisoned. Such a serious blasphemy would likely enrage those devout to the god or goddess insulted. It is possible that Anastacia said something negative about Fina. Being in love with this goddess, Lautrec may have killed Anastacia as punishment. After killing her, Lautrec does not use her soul, so it may be that he hangs onto it as a trophy. Or a gift.
2 Where Lautrec Was Going When The Player Meets Him
Considering Lautrec's connection to a goddess, it makes sense for him to head to Anor Londo, where the player can invade his world and retrieve Anastacia's soul. Being in love, obsessed, or both, with Fina may be causing him to try and find her. The logical place to start would be the city of the gods itself, despite having been void of most deities for quite some time. Maybe he was taking the firekeeper's soul to his beloved goddess as some sort of gift.
1 Rebirth Of A Killer
Lautrec is not the first cold-blooded murderer in a FromSoftware game. Yurt, from Demon's Souls, appeared in the franchise before Lautrec and was quite similar. He wore golden armor, had a similar helmet, and wielded two shotels and a parrying dagger. Furthermore, Yurt also would kill NPCs if the player did not take him out first. It seems likely that Lautrec is the spiritual successor to this assassin, both in form and function.