Carl Lucas, the man who would one day be known as Luke Cage, was arrested for a crime he didn't commit. While in Seagate prison he was nearly consumed by rage, fighting constantly with his fellow inmates. When he became the subject of an unusual experiment, though, he gained superhuman strength, and skin as tough as steel. With these abilities at his command, he tried to better himself, and to clear his name. If you want to bring this kind of character to your Pathfinder game, then this guide should help you get started.
If you're looking for other heroes (and villains) from Marvel's lineup, as well as conversions for the cast of Game of Thrones, as well as Badasses of History, the Character Conversions page on Improved Initiative has you covered.
Race, Attributes, and Stats
Before he became Luke Cage, Carl Lucas had a rough upbringing. Involved in minor criminal offenses, he was never afraid of a fight, and he had the headstrong impulses of youth. He did, in time, learn to control himself, and he gained a greater understanding of the ways of right and wrong. His Strength and Constitution are important, but so are both his Dexterity and Wisdom scores.
When it comes to his background traits, Carl Lucas led a full life before the incident that turned him into Harlem's most notorious hero. A lifetime of brawling could be represented by the trait Heavy Hitter (+1 trait bonus to damage with unarmed attacks), and if you want to represent his sheer physicality after the experiment you could take Muscle of The Society, which treats your Strength as +2 higher when breaking doors, lifting portcullis, and determining your carrying capacity. Even the trait Bred For War (+1 trait bonus on Intimidate checks and to your CMB because of your size) would fit.
Of course, Carl Lucas is also a wanted man. If you want to represent that, and get a third starting trait, you could apply the drawback Infamous. This gives you, and your allies, a -4 penalty to Diplomacy checks because of the crime you're linked to. Of course, those who are enemies of the authority trying to bring you down don't care, and in those cases the negative doesn't apply.
Becoming Luke Cage
Luke Cage, the main with the stainless steel skin, is known for fighting battles that would leave less powerful people crippled, or dead. Part of that comes from his unwavering sense of purpose, and refusal to give up. Part of it comes from his bulletproof hide, and his unwillingness to move. You hit him with a truck, and the truck is going to stop.
One of the best starting places for stacking these powers is the Monk of The Sacred Mountain archetype on page 114 of the Advanced Player's Guide. You trade out evasion and improved evasion, along with slow fall and high jump, but in return you gain natural armor, damage reduction, and when you stand your ground you are impossible to move, as well as difficult to damage. The ability Adamantine Monk even states that your skin and muscles have grown so tough they can ignore damage.
That does mean you're locked into a lawful alignment, but given that Luke seems to follow his own code when it comes to being a hero, that seems quite fitting.
Skills and Feats
Luke is a man of many talents. For his skills, you may want to take Perception, Acrobatics, Sense Motive, and Intimidate. If you have the skill points, and you're going with the TV version of Luke as a preacher's son, then Knowledge (religion) would also be appropriate. Stealth is useful, but rarely something we see Luke use... unless you consider pulling up his hood and walking carefully to be a Stealth check.
When it comes to his feats, you have a lot of choices to make. Especially since the monk gives you access to so many bonus feats that would normally be too difficult to put on your sheet. For example, you can take Deflect Arrows as a first level bonus feat. Given that bullets can be deflected with this (as per the rules in Ultimate Combat), this allows you to do what Luke does in the restaurant fight. Combat Reflexes means that no one can just walk past him without provoking an attack of opportunity (which is befitting for the guy who tends to be the front line in whatever team he's a part of). Improved Grapple, and Improved Trip, are both on the list, and you can take them without meeting the prerequisites. Though if you're going to max out a particular combat maneuver, it's important to take all the feats in the tree in order to get the full effect of the feats.
As to Luke's regular feats, well, he's a bit of a combat monster. Power Attack is probably the most fitting, especially for Power Man, but you might also want to consider taking Improved Sunder. Luke turns a lot of weapons into balls of steel, and given the bonuses to combat maneuvers from his class and background trait, this can be a nasty surprise for your enemies. Because if someone needs that sword or shield to fully realize their potential, taking it away can cripple them. Destroying a holy symbol, or bonded item, can also be bad news for an enemy spellcaster. If you want to be a one-punch style fighter, then taking Furious Focus and Vital Strike will let you swing one, big blow per round when you need all your bonuses, or you have to move before you hit.
If you know you're going to be in an urban environment for the whole campaign, you may wish to invest in Street Style, Street Sweep, and Street Carnage. These feats allow you to bull rush opponents you hit with unarmed strikes, tripping them and staggering them. Which would produce the effects you typically see when Luke goes toe-to-toe with someone. If you're going to be adventuring in a lot of environments, though, you might want to take Pummeling Style, Pummeling Bully, and Pummeling Charge, which allow you total your damage before applying DR, knock opponents prone with your unarmed strikes, and perform a full-attack at the end of a charge respectively.
How Close to The Canon?
Gear, Additional Powers, and Story
One of the most common complaints when adapting comic book characters into the Pathfinder setting is that it's hard to make them feel really super. After all, the rules don't always support the concept. Even a high-level Monk of The Sacred Mountain will only have DR 3 or 4, which will jump to DR 6 or 8 by spending a ki point. While thematically appropriate, that might not be what you think of when you picture a bullet-proof hero.
There is a way to juice Luke up, if your DM is willing to let you pursue it. Simply select spells that mix well with his class features, and seek a way to make them permanent. Barkskin, for example, will boost his natural armor, making him a real tank when it comes to brawls. Other spells, like Owl's Wisdom, Bull's Strength, or Bear's Endurance can create a permanent enhancement bonus, leaving Luke walking around with stats that are a bit more reflective of what people think of when they think of a superhero. And while out of game you might have to pay gold for the services, in-game you could claim it is the result of the same experiment that made Luke what he is.
When it comes to Luke's gear, there's a bit of an inside joke you could make. Classic Luke Cage, when he was still working as the Hero For Hire and went by the street handle Power Man, wore a pair of heavy bracers, and a headband that really looked more like a tiara. Bracers of Armor, and a Headband of Inspired Wisdom would be great for representing this throwback look. You could even claim that your Belt of Giant Strength or Belt of Physical Might is in the shape of a chain... for reasons.
Lastly, though, you need to decide how much of Luke's story you're going to keep, and how much is going to be your own. Is he the son of a cop with a misspent youth who finally saw the light? Or is he a preacher's kid who did some time in the armed forces as a way to skate on some criminal mischief? Was he a willing volunteer for the experiment, or was it forced on him? Is he using his powers as a mercenary, or is he just trying to help people?
All of that is up to you.