One of the key elements is Johnny Blaze's selfless intention at first. He was willing to sacrifice a lot to save his foster father. The deal with Mephisto is crucial as it's what triggered the whole transformation. Also, the powers that come with being the Ghost Rider, like the Penance Stare and the ability to control hellfire, are important elements. And not to forget, his iconic motorcycle which is an integral part of his identity as the Ghost Rider.
Well, the character of Johnny Blaze is fundamental. His backstory as a stuntman gives context to his later transformation. The deal with Mephisto is the turning point. It's a Faustian bargain that leads to his cursed existence as the Ghost Rider. The powers he gains are key elements too. The flaming skull is not just for show; it represents his connection to the supernatural. The Penance Stare is a moral - ish power that reflects his role as a spirit of vengeance. And his motorcycle, which has a supernatural nature itself, is a symbol of his journey as the Ghost Rider, allowing him to travel to places where he can carry out his vengeance.