Sparda is a mighty and tremendously powerful demon whom is widely hailed as the 'Legendary Dark Knight'. This is due to him having rebelled against his masters and single-handily defeated the armies of Hell along with its own generals and ruler. Sparda was also one of the Knights of Hell and regarded as the strongest and most skilled member of the Knights. In fact Sparda was so powerful that his prowess alone would easily help him reach the rank of a lord of Hell.
Before this all occurred, Sparda once resided in the Inferno and was feared as the most powerful demonic swordsman in all of Hell, having virtually no equal. He was also known to be explicitly cold, ruthless, and calculating in battle; traits which earned the respect of his peers and superiors, and thus appointed him as being the general of legions of the damned. While Sparda was cruel, he did possess great wisdom which has come to even inspire many demons.
At some point in time, Sparda began to see the tyranny his masters would inflict on the humans and turn away in disgust. This resulted in Sparda rebelling against the lords of Hell, and fighting the innumerable amount of demonic soldiers commissioned by the Hell lords to raid and destroy mankind across the globe. He alone defeated the hellish host, before moving on to the Emperor of Darkness himself; Mundus. Sparda defeated Mundus, sealing him into a marble vault, and what was left of Mundus's armies retreated back into the demon world.
After their defeat, Sparda used his blood as well as that of a mortal priestess to seal away Hell from the mortal realm for all eternity. However, he realized that victory was not so easily attained as there were six more Gates stationed across the world. And thus, Sparda declared that if he were to completely cut off the connection between Hell and the human world, he would have to destroy the six Gates while also defeating those whom own it; those individuals being none other than the Seven Princes of Hell.
While traversing across the world, Sparda reached and destroyed each of the six gates whilst also defeating the seven princes, although, it was reduced to six since Mundus was a member of the Seven Princes. His last battle was against the Dark Lord, Satan, and legends dictate that Sparda and Satan fought in a battle that could have quite nearly ravaged an entire continent. After a long and hard-fought battle, Sparda defeated the King of Hell and banished him back to the Inferno. His banishment consisted of conjuring a powerful binding spell that tied the princes' to their respective circles and prevent them from going any further near the physical world. It is said that Sparda also received aid from the archangel Gabriel to accomplish this.
Due to his brave heroics, Sparda was revered and praised as a hero, but while he would not see himself as such, he nonetheless accepted his role as a protector and savior of the humans. And thus, Sparda dedicated himself to finding and eliminating any supernatural threat that would harm or destroy mankind for years to come. Although, as years passed, Sparda would slowly fade into myth but would continue his missions in secrecy. Sometime in the twentieth century, Sparda would eventually meet and fall in love with a human woman, and this resulted in her giving birth to twin sons whom possess Sparda's enormous demonic power. After that, Sparda disappeared, never to be seen or heard from again. But his actions would be remembered and influence many for years to come.