The Tin Man was originally a man named Nick Chopper. He kept having parts of his body chopped off in various accidents in the woods. Each time, he had them replaced with tin parts. Eventually, he became fully made of tin and lost his heart, both literally and figuratively. His transformation led him to a life of seeking a heart and a sense of purpose.
The Scarecrow was once a young man named Boq. He was a Munchkin studying at Shiz University. He was cursed by Elphaba's magic when she tried to save him from being turned into a statue. This led to his transformation into the Scarecrow. He was left with a brain that he felt was not fully functional, but his love for Elphaba remained.
The Scarecrow was Boq, a Munchkin. He got cursed by Elphaba's magic and turned into a scarecrow. He always thought his brain was not as good as before. The Tin Man was Nick Chopper. His ax had magic that made him cut off his body parts which were replaced with tin. So he thought he lost his heart.
The Scarecrow, as Boq, was in the middle of a love triangle - loving Glinda while Elphaba had her own feelings for him (in a different way). His new form as a Scarecrow gives him a different perspective on life in Oz. The Tin Man, being made of tin, is more focused on regaining his heart. He has a sense of being incomplete without it, and his back story is about his journey towards that goal. For instance, he had to endure the pain of each body part being chopped off and replaced, which led to his current state.
One interesting fanfiction could be about the Scarecrow and Tin Man going on a new adventure in a different magical land. They might face new challenges and make new friends.
You can try fanfiction websites like Archive of Our Own (AO3). There are often a lot of different stories about various characters there, including the Scarecrow and Tin Man.
The most important element in the Tin Man's back story is the sequence of events that led to his becoming a tin man. Starting with his life as a woodsman, then the introduction of the cursed axe which caused him to lose his body parts one by one. The influence of the Wicked Witch through the spell on the axe cannot be ignored either. And his resultant state of being without a heart, which is central to his character's development in the story.
The Tin Man in 'The Wizard of Oz' was once a normal man. He was a woodsman. But due to the Wicked Witch's spell, his axe was cursed. Every time he used it, he would accidentally chop off parts of his own body. So, bit by bit, he replaced his body parts with tin until he became fully made of tin. This made him lose his ability to love and feel emotions at first, but through his journey with Dorothy and others, he regained his heart, both literally and metaphorically.
The Tin Man is a character from 'The Wonderful Wizard of Oz'. He was seeking a heart to feel emotions.
The key elements in the Tin Man's back story are multiple. Firstly, his original identity as a woodsman is crucial as it sets the stage for what happened to him. Then, the spell on his axe by the Wicked Witch is a central point. This led to his body parts being replaced with tin. His quest for a heart from the Wizard is also very important as it drives his actions in the story. His new form as a tin man, which made him lose his emotions, is another key element.
Well, the Tin Man's real back story is really quite sad. As I said, he was a woodsman. He had a job to do, cutting trees. But that evil witch messed things up for him. His body parts got chopped off bit by bit while using that cursed axe. Each time, he had to get a tin replacement. Eventually, he became this tin man. And all he wanted was to be able to love and feel again, so he set off to see the Wizard. He was a very kind - hearted man before all this happened, and his friends in the story helped him a great deal on his journey to get a heart.