These two brainiac baddies are "B" class cranium crooks, i.e. they have the requisite intellect and wicked gravitas to pull off being arch-criminals... but not the endearing evilness to match their peers.
Thaddeus Bogus Sivana Junior was the aspiring son of, you guessed it, Thaddeus Bogus Sivana Senior, the latter being Captain Marvel's greatest adversary. However, despite having a lengthy career causing Fredy Freeman (also a junior, as in Captain Marvel Junior) some level of anxiety, alone Junior was unable to match the dasterdly deeds of his papa.
In fact, perhaps his most significant act was actually a mishap, as his father had finally devised a method of removing the entire Marvel Family and their fellow Fawcett friends from planet Earth-S thanks to the element known as Suspendium. However, junior decided to pat senior on the back to congratulate the villain and instead captured both and his sister Georgia in the same snare! As a result, the Sivana Family was left out of commission during the same period as their opposite numbers for decades!
After being released from this floating prison in space, the most Sivana Junior accomplished was to styme both foe and father with his incompetent intellect. Needless to say, this is world's wickedest wednesdays not necessary world's most successful.
Over at Charlton's Earth-Four, Kong whom we previously considered had a modest career during his three encounters with the Son of Vulcan. Utilizing rotund robots, slicing swords and destructive devices, Kong attempted repeatedly to rid himself of his super-powered enemy and make a name for himself. Like Sivana Junior, he ended up a more or less a B class brainiac. And there are several just crooks in Mighty MLJ that fit that bill.
In 1954, aspiring comic book publisher Charlton purchased the rights to several prominent characters from the expiring Fawcett Comics, such as Ibis, Golden Arrow and Lance O'Casey. In 1980 and 1985, DC Comics purchase Fawcett's Marvel Family then Charlton's Action Heroes, and the two were linked once more, now on parallel Earths, Four and Shazam.Now the MLJ has been added to their stable of characters, we examine the parallels in this series.