One key element is that he was a normal detective, Shinichi Kudo, and then became a child, Conan. The fact that he has to hide his true identity from those around him, especially Ran Mouri, is important. And the overarching plot of finding a way to reverse the effects of the drug and take on the criminal organization is a crucial part of his back story.
Well, first of all, his identity change is a major element. Shinichi was a well - known detective, but as Conan, he has to use different tactics. Then there's the mystery of the drug that changed him. He's constantly on a mission to not only solve the cases he encounters but also to find out more about the drug and the people behind it. His relationship with the people around him, like his friends and Ran, is also shaped by his new identity, which is an important part of his back story as well.
One key element is his Texas upbringing which gives a certain flavor to his music. Another is his use of personal experiences in his songwriting.
One key element is his birthplace, Cimmeria. It was a rough and unforgiving land which made Conan tough. Another is his family or tribe in Cimmeria that instilled certain values in him. Also, the constant threat of danger in his homeland forced him to develop combat skills early. And his natural inclination towards adventure which led him to leave Cimmeria.
The key elements include Conan's role as a barbarian hero. His physical strength is a major part. Also, the presence of magic in his world. Magic often creates the enemies he has to face, like evil wizards. Another element is his exploration of different terrains, which adds to the adventure aspect.
Well, one key element is that there was this serial killer, Charles Lee Ray. He was on the run from the cops. Then there's the voodoo aspect. He managed to use voodoo to get his soul into the doll. And of course, the fact that he could then use the doll's form to carry out his evil deeds, which is also a very important part of his back story.
One key element is his life in Ionia before the accusation. He was part of a community of swordsmen. Then, of course, the sudden accusation which turned his world upside down. His exile made him a pariah. He had to fight not only for survival but also to prove his innocence. And throughout all this, his swordsmanship evolved as he faced various foes during his exile.
Immortality and his time as a thief are key elements.
One key element is his super - speed. It's what makes Sonic unique and able to take on Dr. Eggman. Another is his world with different zones like Green Hill Zone. Also, the presence of Dr. Eggman as his main antagonist is crucial.
One key element is Negan's pre - apocalyptic existence. We don't know a whole lot about it, but it's the starting point. Next, the Saviors. He built this group from the ground up. It became his power base. The way he ruled the Saviors, with an iron fist, is also part of his back story. And Lucille, his beloved bat. It was named after his wife, and it was a tool for him to enforce his will. His wife's death also played a role. It was a catalyst for his transformation into the ruthless leader we know. All these aspects intertwine to form the complex back story of Negan.
One key element is his Chiss origin. It shapes his identity and how he approaches things. Another is his entry into the Galactic Empire and his rise through its military ranks.
One key element is his Russian military origin. Another is his training for special operations.