The rest of the story concentrates in comparing and contrasting the two rivals during a race in "The Heart of Africa" (a recurring phrase in the story). The race is supposed to determine which one of them deserves the title. The two characters resemble each other both in appearance and behavior though their main common point seems to be that they are extremely competitive and neither of them can accept the idea of someone else being superior or equal to them. Flintheart, like Scrooge, keeps a percentage of his fortune in his own Money Bin, identical to that of Scrooge, while the rest of his fortune is invested in a world-wide financial empire of his own that equals that of Scrooge (though Scrooge's main sources of wealth are his industries while Flintheart's are his diamond mines). Their main difference seems to be their way of life. Scrooge's Money Bin is at the center of Duckburg, Calisota, USA, a constantly expanding industrial city, while Flintheart's is in the center of a valley, located somewhere in the lands around Limpopo, surrounded by wildlife and away from human activities. While Scrooge finds himself surrounded by an extended family (see The Clan McDuck, Duck family and Coot Kin) and a large number of allies and rivals (see Scrooge McDuck Universe), Flintheart lives a life of solitude and seems to have no family, friends or for that matter rivals except Scrooge himself. While Scrooge has his nephews helping him or advising him, Flintheart faces every situation alone. This apears to have hardened him - he is considerably more ruthless than Scrooge - but also leaves him vulnerable to being simply outnumbered by his rivals. Even at the end of the story when Scrooge has won and Flintheart passes out after finding he is only second best, he has to be carried home by Huey, Louie and Dewey since he has no one else there to help him.
The solitary South African re-appeared to challenge Scrooge to a rematch in The Money Champ, first published in September, 1959. This time the confrontation takes places in Scrooge's grounds in Duckburg with the city's population witnessing the event. This time they only count their wealth in cash and not their investments and have to liquidate much of their fortunes. Flintheart uses a number of dirty plots against Scrooge but his plans backfire when their cost in money also costs Flintheart his chance at victory. The story adds little to what was established in the previous but for the first time some panels concentrate on Flintheart's thoughts, revealing that his insecurities about his own worth are the driving force behind both his efforts to best Scrooge and his dishonest tactics (since he doubts his ability to win in a direct confrontation).
Barks would use Flintheart for a third and last time in So Far and no Safari, first published in January, 1966. This was one of the last stories Barks created before his retirement. The themes of this story are considerably darker than the two previous ones. Flintheart's intentions towards Scrooge are clearly depicted as murderous. The story starts with Scrooge planning to participate in an auction for an old South African gold mine. It is considered exhausted but Scrooge's mechanics believe that the main vein of gold hasn't even been reached. While Scrooge is piloting his private plane over South Africa, with Donald, Huey, Dewey and Louie as passengers, Flintheart appears piloting his own private plane. It is equipped with machine guns and he proceeds to shoot down Scrooge. While Scrooge is still trying to reach the auction Flintheart repeatedly tries to get rid of him. When Scrooge manages to reach the Kalahari Desert, Flintheart's plane is revealed to be a bomber as well. Flintheart proceeds to bombard the area where Scrooge and his nephews are, but misses. When he returns for a second bomb run, the Ducks have dressed some rocks with their clothing and have taken cover elsewhere. Flintheart mistakes the rocks for his targets and proceeds to destroy them. As he comments, his rivals are now dinner for the jackals. His victory is short-lived. He was flying low and the bomb explosions damaged his plane's fuel tank. He crash-lands the plane and finds himself in no better condition that Scrooge.The rest of the story presents Scrooge's and Flintheart's rival efforts to cross the Kalahari and reach the auction. The end of the story finds them at the auction, tired from their hard trails but still rivaling each other, while an exhausted Donald has fallen asleep. It is considered Flintheart's darkest appearance and among his strongest and most memorable ones.
The twenty years that followed his creator's retirement threw the character into relative obscurity. He made infrequent appearances in stories that are generally regarded as lower in quality to those of Barks and largely forgettable. He wasn't nearly as recognizable as other rivals of Scrooge,like Italian sorceress Magica DeSpell, who appeared more oftenly . Flintheart returned to prominence in 1987.
In this year Keno Don Rosa created his first storie "The Son of the Sun", first published in July, 1987. Though his drawing efforts for this storie are rather crude by the standards he would later set ,it still managed to get the attention of Disney comic fans. Rosa's detailed style of drawing, references to Barks stories (by then considered classic) like Lost in the Andes, detailed references to often obscure historical figures and events and strong characterization (considered by Disney comics fans to be rare in European stories and lacking in American ones since Barks' retirement) would later make Rosa considered one of Barks most popular "Successors". Those themes are all evident in his first storie. It begins with Flintheart questioning Scrooge's many successes as a treasure-hunter. He claims that discovering riches that are already concentrated by others is not that hard and that he could do it better than Scrooge if he decided to try. Pretty soon he is following Scrooge and his nephews in their latest treasure hunt. Locating a hidden temple of Manco Capac, legendary founder of the Inca dynasty, hidden somewhere in the tops of the Andes and according to inscriptions earlier found by Scrooge suppossed to contain a great treasure. In the course of the storie Flintheart is re-established as one of Scrooge's most charismatic, resourcefull and ruthless rivals.
Rosa, who admits to have a soft spot for the character, has used Flintheart in a growing number of stories. And has offered him a sort of origin. In his stories Flintheart is a Boer from the province of Transvaal. He was born in the 1860s and first met Scrooge during the Gold Rush of 1886 (the main effect of this Rush was the foundation of Johannesburg). Like Scrooge, Flintheart was born in poverty and was working his way up the financial ladder. While unsuccesfuly searching for diamonds, he attempted to steal the foundings of more succesfull fellow miners. As a result he was tied to the horns of a passing by water buffalo and the animal was then sent running. Flintheart was found and saved by Scrooge. Flintheart offered to be the guide of the recently arrived goldminer from Scotland, since he knew the territory. Scrooge accepted him as a needed companion and friend. But at night while Scrooge was sleeping, Flintheart stole his ox-cart along with all his equipment and supplies and left him alone in the wilderness. Having underestimated Scrooge , he was surprised when Scrooge caught up to him , furious and vengeful. When Scrooge finished with him , Flintheart was publicly humilated ,thorougly bitten and imprisoned for theft. The two rivals made vows to themselves that helped shape some of their character traits. Scrooge vowed to never trust anybody ever again, in order not to be betrayed again.Apparently the source of Scrooge's distrust towards others whether they are allies, rivals or complete strangers and the reason he is secretive about his thoughts and emotions. On the other hand a completely defeated Flintheart ,vowed that he will work to become so rich that nobody can humiliate him again. His motivation behind his search for wealth. (see Life and Times of Scrooge McDuck - Part VI:The Terror of Transvaal) .According to Rosa's unofficial timelines it would take him twenty years of hard work as a diamond miner till finally he became rich in 1906 by his profits. He would spend the next fifty years, till 1956, working his way up the financial ladder both by hard efforts and dishonest methods when needed. He would become a worthy match for Scrooge and would die during the late 1960s or early 1970s, after a century of solitary life.
While the Rosa version is arguably the most popular, an animated version of the character appeared in the TV series Duck Tales, that started airing on September 11, 1987. The Second Richest Duck was among the series most prominent characters and this helped his introduction to a wider audience. But some drastic changes came to the character. To avoid connections to South African issues that were then a cause of world-wide attention and concern (see apartheid) his origin was changed from South African to Scottish to match that of Scrooge. He was depicted as wearing a traditional Scottish kilt and his voice actor Hal Smith (Harold John Smith ,August 24, 1916 - January 28, 1994) gave him a thick Scottish accent. His place of residence was also changed to Duckburg. The previously unconnected to him Beagle Boys were now depicted as working for him in an occasional basis.
Combining elements of the Barks/Rosa and the Duck Tales versions of the character, other comic book creators started using Flintheart in their stories and in time he became one the most frequently appearing characters. In these stories he is depicted as an influential member of Duckburg's Billionaires Club , which also includes Scrooge and John D. Rockerduck. A number of stories have attempted to reconcile the two versions of his origin by claiming that either him or his parents had immigrated to South Africa from Scotland. Some stories also depict Flintheart as dividing his time between his homebase in Limpopo Valley , in order to be closer to his diamond mines, and his mansion in Duckburg ,from where he can keep an eye on Scrooge's activities and oversee the expansion of his financial empire to the USA. Others are trying to fill the blanks in his background. But all in all Flintheart has become a very prominent character.