Like Bois-Guilbert and Front-de-Boeuf, Maurice De Bracy is one of Ivanhoe's main Norman villains. His villainy focuses around Rowena. When Prince John offers to marry Rowena to De Bracy so he can control her rich lands, De Bracy doesn't think, "What? Marry a girl I've never met, just for money!?" No, he immediately says, thanks, Prince! Sign me up! I want those lands, and I don't care what kind of a lady she is: "If the lands are to my liking, my lord [...] it will be hard to displease me with a bride" (13.14). De Bracy is careless and greedy, and his attitude towards Rowena proves it.
De Bracy is the genius who, along with Bois-Guilbert, has the bright idea to kidnap Rowena and her dad and then stage a fake "rescue" so that she'll fall into his arms with gratitude. (Of course, the fake rescue never really happens.) If it weren't for De Bracy's disastrous plots, the violence at Torquilstone could have been avoided entirely.
Still, in spite of all of his wrongdoing, we kind of have a soft spot for De Bracy. Scott gives him some appealing characteristics to balance out his general foolishness. Even though De Bracy tries to go through with this idiotic idea of tricking Rowena into marrying him, he loses his nerve once he actually sees Rowena face to face. Rowena isn't stupid, after all: she knows De Bracy hasn't rescued her.
When Rowena tells De Bracy at Torquilstone that she has no interest in him at all, De Bracy suddenly regrets getting into this whole mess in the first place. Clearly De Bracy willingly goes along with whatever his more forceful friends suggest (in this case, Bois-Guilbert). De Bracy wants to look cool, but he's not as evil as his bullying friends. When De Bracy sees Rowena crying over his proposal of marriage, he admits to himself that he can't carry out his plot to force her to marry him:
If [...] I should be moved by the tears and sorrow of this disconsolate damsel, which should I reap but the loss of those fair hopes for which I have encountered so much risk, and the ridicule of Prince John and his jovial comrades? And yet [...] I feel myself ill framed for the part which I am playing. I cannot look on so fair a face while it is disturbed with agony, or on those eyes when they are drowned in tears. (23.31)
What's more, De Bracy seems genuinely ashamed of himself after Torquilstone, when he asks Rowena for her forgiveness for her kidnapping. Rowena forgives him because she feels like she should, but she also tells him that she will never forget all the heartbreak and agony he's caused. (Which is totally fair: De Bracy does ruin some lives with this idiotic plan.)
We'll also give this to him: De Bracy really cares about medieval knightly codes of honor. When he ambushes Rowena and Cedric, Rebecca and Isaac are part of the party, and they are secretly escorting a wounded and unconscious Ivanhoe with them to York. When De Bracy looks into their horse litter, he immediately recognizes this fallen knight as Ivanhoe. But De Bracy doesn't tell the other Normans who the wounded knight really is. In fact, he claims that it's one of his own comrades, injured in battle from the capture of Cedric and Athelstane. He hides Ivanhoe's identity because it's dishonorable to take advantage of another knight when he's down. That's a level of commitment to fair play that other Normans, like Front-de-Boeuf and Bois-Guilbert, would probably laugh at.
When King Richard I, disguised as the Black Knight, saves De Bracy's life from the outlaws after the battle at Torquilstone, De Bracy admits that he owes the king a personal debt of gratitude. That's why De Bracy tells Prince John straight out that he can no longer fight against the king – it would be dishonorable.
De Bracy is also hilariously superstitious. Practically every time he says something, he swears by several saints to prove his spiritual devotion. He doesn't appear to have a strong sense of faith or Christian conviction, but he does worry that if he doesn't show extreme reverence to the saints and their images, he might get into trouble.
De Bracy's obsession with showing religious faith instead of necessarily feeling it also extends to his knightly duties. He breaks two major rules of chivalry by (a) kidnapping Rowena, even though knights are supposed to keep ladies safe; and (b) rebelling against King Richard I, even though the king is his sworn lord. In both cases, when he has to confront the reality of what he's done he feels guilty. It would be preferable to actually live by the codes of knighthood in the first place rather than feel bad when he breaks the rules. But at least he has remorse, which is more than we can say for Brian de Bois-Guilbert.
It's because De Bracy doesn't seem all that bad that we're okay with the fact that he gets away in the end. When De Bracy realizes that King Richard I is back to stay, and that Prince John's rebellion is never going to work, he flees the country. In the last chapter we find out that De Bracy has gone "into the service of Philip of France" (44.45). We hope for King Philip's sake that De Bracy is more loyal to him than he was to Richard.