Mikkelsen's role is somewhat simple early on as the film mostly focuses on Bond taking down some of the men Le Chiffre hires rather than the Le Chiffre himself. Mikkelsen still has a few scenes where he put in his orders or offers his own services. Mikkelsen makes himself a true Bond villain though as he carries himself with such a natural class and dignity while still exuding considerable menace. Mikkelsen's manner is impeccable as he suggests Le Chiffre intelligence quite effectively and makes him an intimidating presence even while every thing we see suggests that Le Chiffre might not be all that formidable. Mikkelsen's role quickly becomes more substantial when the film reaches its focal point the titular Casino Royale poker game where Bond and Le Chiffre face off for a gigantic pot of money. Naturally, in true Bond villain form, Mikkelsen executes well the routine as Le Chiffre greets Bond in a friendly way while clearly having a deadly intent in his eyes.
For awhile Mikkelsen thrives in technically a very restricted role as he must trade starring daggers with Bond on the poker table. Mikkelsen is great at this as he does have a great stare that carries a menace even when there isn't anything particularly menacing about what he is doing. Mikkelsen brings the needed intellectual smugness to the role making it sting particularly hard whenever Le Chiffre gets the better hand than Bond. His delivery of "oops" when he reveals that one of his cards has caused Bond to lose big time is just about perfection. The interesting that Mikkelsen though does make Le Chiffre a bit more than a villain we should despise. This is best seen when Le Chiffre, and his girlfriend, are threatened by a couple of the terrorists he acts as the banker for. Mikkelsen is great in the scene as he portrays a very honest desperation in the Le Chiffre showing that the card game is a matter of life or death for him. Although Mikkelsen still keep Le Chiffre reserved as a man, he still gives the sense that there is a humanity in him.
Mikkelsen actually is incredibly good at making Le Chiffre a strong presence despite not having a major villain scene for the majority of the film. This does come with his last scene where he decides to simply torture Bond to get the money, utilizing one of the painful torture methods a man could imagine. Mikkelsen is just about flawless in this scene as he brings the needed cold intensity as Le Chiffre brutally interrogates Bond. What I love the most though is how varied Mikkelsen's performance in the scene. He does not just show Le Chiffre as torturing for the fun of it, although Mikkelsen does portray a bit of satisfaction, but that he is trying to get something. There is that desperation from before as again Mikkelsen suggests that Le Chiffre is trying to save his own life by taking away Bond's. My favorite part though are his downright brilliant interactions with Craig. They play off each other so well in the scene as they certainly never hold back on creating visceral impact of the scene, yet they even through in a bit of dark humor as they still are playing a small game of wits. The best single moment though, that I absolutely love from Mikkelsen is after Le Chiffre has tried everything to get to Bond, and Mikkelsen is so genuine as he shows that Le Chiffre can't help but laugh at Bond's resilience. Mikkelsen even gets to top it off with the great last moment where he makes Le Chiffre's fear so palatable that you almost feel sorry for him. Mikkelsen is an excellent Bond villain as he goes far beyond the call duty here. He certainly meets all the standard requirements of being an enemy of 007, but he goes further than that with the part. His Le Chiffre is more than just an obstacle to be overcome as he creates an actual man who happens to cross paths with James Bond.