T'Challa of Wakanda is an exceptional individual in a world of already exceptional individuals. The hereditary monarch of Wakanda, he has recently stepped down from his position but possesses such fame and power he could easily retake the throne. So far, T'Challa has no desire to do so because he no longer trusts himself with such decisions. Which is ironic given his most crippling character flaw is an almost Doctor Doom-levels of pride.
From birth, T'Challa has been educated by the finest tutors in the world and put through a punishing physical regime. Wakandan medicine meant he was a perfect physical specimen before he subjected himself to the magical root that bestowed upon him skills far beyond those of normal mortals. These, too, he supplemented with a vibranium battle suit capable of absorbing anything below an Iron Fish-enhanced blow.
T'Challa would have made an excellent monarch to the traditionalists of Wakanda but for the fact his father gave him a mission: bring his land to into the outside world. T'Challa might have turned against his father's vision for Wakanda (continuing his land's isolationalism for another few decades at least) if not for the fact T'Chaka died at the hands of Ulysses Klaw.
T'Challa's hatred for the Klaw is not only because the sonic villain inflicted such a crippling personal loss but he is such a PATHETIC villain. T'Challa considers it an insult his father died at the hands of a C-level Avengers villain whose only reason for survival is his incorporeal nature.
T'Challa has thus committed himself to freeing Wakanda from the shackles of tradition and bringing the land into the 21st century (which is hard for a society whose technology is closer to the 23rd). He made contact with the Fantastic Four first as part of a calculated attempt to introduce Wakanda through superheroes. T'Challa's keen intellect and political savvy made him believe he could move freer through the world stage by assuming the identity of a costumed crime-fighter than as a monarch.
He was right.
T'Challa's membership in the Avengers was less because he desired to be a member of the team than for the chance to spy on the world's most powerful people (as well as the unparalleled access to the First World's military secrets). Later, he would appreciate the Avenger's bravery, selflessness, and how many times they'd saved his homeland from threats they hadn't suspected existed. He decided to become the Black Panther to the world, helping all of its peoples.
T'Challa takes a special interest in the welfare of African Americans as well as Africans in general.
This is an uncommon attitude amongst Wakandans who see about as much in common with their fellow Africans as they do [insert demeaning reference of your choice]. T'Challa has opened up Wakanda to thousands of refugees and also run countless programs designed to improve the lots of these individuals.
Somewhat like the late Hugo Chavez, T'Challa took especial pride in helping alleviate the poverty of Americans as he considered this a nice shap in the United States' face (The USA's diplomats having frequently reacted in a patronizing fashion to Wakanda in particular and Africa in general).
Unfortunately, being the Black Panther to the world and monarch of Wakanda have frequently been at odds. T'Challa's charity efforts both abroad and at home have resulted in numerous groups banding together in order to overthrow him. Wakanda has never had a crime problem before and still doesn't but it does, now, have numerous issues with terrorists as well as extremist political movements. The White Wolf, the unfortunately named Man-Ape, Erik Killmonger, and the mad Bishop Acheb have all taken T'Challa's place as ruler at various times.
The White Wolf is one of the most bizarre subjects in these "back to tradition" movements as he is T'Challa's adopted Caucasian brother Hunter. Almost no one likes Hunter in Wakanda but he is one of the most deeply devoted Wakandans there is--acting twice the zealot for half the respect. Hunter knows it is not the quantity of one's friends but the quality, though, and has the loyalty of Wakanda's former secret police.
Bishop Acheb is a foe that T'Challa hates more than any of his other's, however. Bishop Acheb seduced T'Challa's stepmother into betraying the land and ruled over Wakanda using foreign mercenaries for a time--showing T'Challa as unable to protect his homeland in the eyes of the public.
The Man-Ape is a somewhat slow-witted (for a Wakandan--still genius level for everyone else) chieftain of the land who favors a "back to nature movement." He is a mystic of considerable ability as well as a shape-changer but little real threat. Amusingly, he has recently become a catspaw for Gorilla Grodd.
Erik Killmonger's father was conscripted by Ulysses Klaw then killed in battle, disgracing their family and causing T'Challa to exile them. This proved a big mistake as Erik Killmonger used this time to train himself and enhance his body until the point he has abilities equal to Deathstroke. He is unquestionably superior to T'Challa in every way and his greatest threat. Why? Most Wakandans agree Erik Killmonger would make a "better" king and this is knowing he would expel all foreigners.
T'Challa's has attempted to bolster his political position in Wakanda due to these by recruiting strange allies. These include Geo-Force
, a fellow monarch and being capable of manipulating vibranium, and Wonder Woman
. Paradise Island, ironically, proved the only group the Wakandans were willing to treat as equals. He attempted to bring outside mutants in with his marriage to the mutant Storm, herself capable of leveling armies, but that failed due to her heart being with the X-men.
T'Challa had thoughts of wooing Wonder Woman but found themselves ill-matched in temperment.
Amusingly, he found himself far more intrigued by Nubia. Not the least because T'Challa has a type.
The two countries have exchanged philosophy and technology fairly equally ever since. He's also bolstered Wakanda's ties with Arthur Curry's portion of the Atlantean Empire. This proved wise as Aquaman's assistance prevented the casualties from Namor's Phoenix-inspired attack from being much worse. Aquaman dislikes Black Panther's imperious ways but it has proven a boon to his people every bit as much as it has to Wakanda.
Unfortunately, T'Challa's arrogance has lead him to attempt to prove himself against superheroes a little out of his weight class. Because Wakandan kings rule by virtue of their claim to be the strongest and smartest, T'Challa has often sought to improve himself by showing his superiority over his fellow superheroes. T'Chaka did so with Captain America and much of the Justice Society during WW2 but T'Challa's attempts have gone over like a ton of bricks with other heroes.
Mostly because they think he could just ask them to spar.
Despite being an unparalleled mind, T'Challa has lost against virtually every single member of the Justice League he's challenged despite his incredible strategic abilities and a technological base on par with Latveria.
Superman, mesmerized into losing his powers, was briefly overwhelmed until he thought T'Challa was going to hurt someone and pushed himself to the point that he overwhelmed the vibranium's power to deflect attacks. Wonder Woman, simply put, defeated him utterly even with T'Challa's new anti-demigod battlesuit. Batman? Batman said he didn't have time for T'Challa's games so T'Challa MADE time.
T'Challa's abdication of the throne came soon after, even though the public reason was his inability to prevent Namor's attack.
In fact, T'Challa was INSPIRED by Bruce Wayne. The realization there was someone EXACTLY like him and capable of equaling Wakanda's finest told T'Challa the world was ready for his father's dream.
The two have since teamed up against Ra's Al Ghul, Bialya, a Hydra-HIVE alliance, and several other threats. Black Panther has even lead the Outsiders on occasions where Bruce has been tied up on other business.
Being retired from the monarchy and now the High Priest of the Dead has given T'Challa all the time to get to work on fighting REAL threats world wide. The pointers Batman gave T'Challa on his fight with Superman also allowed the Black Panther to defeat Black Adam when said figure decided to conquer Wakanda for self-justifying reasons.
Really, T'Challa has never been happier.
He has also started traveling with the White Tiger as a sidekick and is debating expanding his "family" further.