Terry Sloane was a child prodigy during the early part of the 20th century, who exhibited an advanced intellect and a photographic memory from a very young age. He graduated from high school when he was only eleven, and finished college by twelve. Having honed his mind to perfection, He then pursued extreme physical discipline, and became an Olympic level athlete. Having conquered that world as well, he became an entrepreneur, becoming a millionaire in almost no time at all.
Having accomplished so much at such a young age, he felt lost and depressed, wondering if there was anything left for him to do in life. He even considered suicide. But one night as he was contemplating ending it all, he saw a young woman named Wanda Wilson jump from a bridge. He saved her life, and discovered that her despair came from learning that her younger brother had become a criminal in a local gang, run by a mobster named Big Shot. Sloane became a costumed vigilante named the Mr. Terrific, the defender of fair play, and became known as the "true blue champion of all things fair." As Mister Terrific, he drove Big Shot out of town, and cemented his status as local Super-Hero.
Now a fully-fledged costumed adventurer, Mister Terrific joined the Justice Society and the All Star Squadron during the height of World War II. On his own, he usually fought various street gangs, although he did have an arch enemy in the form of the supernatural villain the Spirit King. Not too many years after the end of World War II, Sloane retired from being a Super-Hero and became an English literature professor at Gateway University.
After several years spent in retirement, Terry Sloane returned to the Super-Hero profession and rejoined the Justice Society part time, although he still maintained his job as a college professor. It was there that found out that his old enemy, the Spirit King, had plans to steal a dangerous device from the campus laboratory. The two old enemies engaged each other one last time in battle, with the Spirit King strangling him to death, all while using the body of the Flash, Jay Garrick, to do his dirty work. The Justice Society of America eventually brought the Spirt King to justice, and Mr. Terrific was memorialized as a great hero of the Golden Age.
Post-CRISIS ON INFINITE EARTHS
Similarly to Terry Sloane, young Michael Holt was a genius child prodigy, learning several different skills by the time he was in elementary school, any one skill which would take the average person years to learn. By the time he was in his early 20s, Holt had 14 PhDs, and was a self-made billionaire thanks to his company Cyberwear, which later became a part of Wayne Industries. On top of all that, he was also a gold medal winning Olympic decathlete.
But despite all the riches life offered Michael Holt, he was struck by tragedy on two occasions, both of which dealt him a serious blow. First, the death of his mentally challenged older brother Jeffrey, followed by the accidental death of his wife Paula and their unborn child. All of his accomplishments seemed to pale in comparison to their loss, and he contemplated suicide. It was at his lowest point that Holt was met by the supernatural being known as the Spectre, who told him the life story of Terry Sloane, the original Mister Terrific. Now Inspired by Sloane's life story, he assumed the name Mister Terrific, and began a career as Super-Hero.
At first, Holt's costume was simply ordinary clothing with a leather jacket that initially had Sloane's "Fair Play" emblem on the back, but his costume got more elaborate later on, as he adopted a T-shaped mask, and a new jacket with the original Mister Terrific's slogan written on the sleeves and "Terrific" written on the back. Armed with his multi-purpose weapons he called "T-Spheres," and with his own considerable gifts, the new Mr. Terrific joined the modern incarnation of the Justice Society of America, and even became its chairman.
After serving for a time as leader of the JSA, he joined the United Nations Security Council's intelligence agency Checkmate, where he initially held the position of White King's Bishop, and later, White King. Thanks to time travel, Michael Holt got to meet his predecessor in the role, Terry Sloane. He also fought against him when his corpse was briefly reanimated as a member of the Black Lantern Corps.
After the events of 2011's FLASHPOINT, reality was altered, and some of Michael Holt's history was changed. He was still one of the world's smartest and most accomplished people, who suffered tragedy after the loss of his wife, after which he started his own company, Holt Industries. He became a Super-Hero and adopted the alias of Mister Terrific, even though there was no previous Mister Terrific in this new timeline. Thanks to his company, Holt became of the most prominent tech moguls on Earth. He also started dating Karen Starr, owner of Starr Industries, who was secretly the Super-Heroine Power Girl.
Holt soon found out that Karen Starr had been secretly breaking into his company lab and stealing technology in order to create a quantum tunnel, which she was building to get back to the alternate parallel Earth she called home, after having become trapped on our world. He then followed her through the rift she had created and discovered another world, which is designated as Earth-2. There, he had several adventures with the group of heroes collectively known as the Wonders, many of whom were alternate versions of his JSA comrades from the previous reality.
After spending a long time in the universe of Earth-2, Michael Holt would eventually come back home to his own Earth. Not long after he returned, he found out about the rise of the Dark Multiverse from Batman, and its threat to the regular Multiverse. He soon joined with the Dark Knight and other heroes to fight off the incursion of the Dark Multiverse, reestablishing himself once more as Super-Hero in his home dimension.
Not long after his journey into the Dark Multiverse, Holt found out that his company had been bought out by greedy industrial billionaire Simon Stagg, which didn't exactly make him happy. Upon returning to his old company's building, now fully owned and operated by Stagg Enterprises, he discovered that Stagg had been performing experiments on Metamorpho, the Element Man, and forcing him to transform himself into the mysterious Nth Metal. This opened a portal to the Dark Multiverse, where Mr. Terrific, along with Metamorpho and the hero Plastic Man were transported to. Together with the heroine Phantom Girl, the four heroes take the name "The Terrifics," and begin to explore the Dark Multiverse together.