Well, the formation of pink diamond in Steven Universe fanfic can vary greatly. Sometimes it's linked to ancient magical rituals or the convergence of powerful forces. It all depends on the creativity of the author.
Pearl, who was once Pink Diamond's servant, is another main character in many of these fanfics. Her loyalty to Pink Diamond, and how that loyalty has changed over time and affected her own character development, is a major aspect in these stories.
One possible plot could be that Steven, having heard so much about Pink Diamond, finally has a chance encounter with her in a dream-like realm. They start to talk about the past, how Pink Diamond used to view the Earth and her complex relationship with the other Diamonds. Steven tries to understand her better and in the process, Pink Diamond gets to see how much the Earth has changed and how her actions still have an impact today.
One interesting story could be about Pink Diamond's early days before she became a part of the Crystal Gems. It might explore her relationships with other Diamonds and how she started to question the Homeworld's ways.
Obviously, Steven and Pink Diamond are the main characters. Steven, with his unique ability to understand and empathize with all beings, and Pink Diamond, with her complex and mysterious past. Their interaction would be the core of the fanfiction.
I'm sorry, I can't directly recommend specific fanfictions as there are so many out there. But you can start by looking on fanfiction.net or Archive of Our Own. Just search for 'Steven Universe baby Pink Diamond' and you'll likely find a bunch of interesting reads.
In steven universe baby pink diamond fanfiction, a great concept is the idea of baby Pink Diamond's dreams and aspirations. Since she grew up to be such a complex character, fanfictions could explore what she hoped for as a baby. Did she dream of ruling over planets? Or was there a part of her that always desired something different? Maybe she was curious about the stars and the unknown from a very young age, which later translated into her interest in Earth. Also, her early interactions with the gem technology around her could be an interesting aspect. How did she learn to use her gem powers? What was her reaction to the grandeur of Homeworld's architecture and machinery? All these elements can make for very engaging fanfiction stories.
A major theme is often power. As Pink Diamond, Steven has a different level of power and influence. Fanfictions might explore how he uses or misuses this power. Also, relationships are a big theme. His relationships with the Crystal Gems, his human friends, and even his enemies might change because of his new identity. For instance, his relationship with Garnet could be affected as she was made in part by Pink Diamond. There could be a lot of emotional turmoil and growth in these relationships.
Well, it depends on what you're looking for in a fanfiction. Some 'Steven is Pink Diamond' fanfictions are more action - packed, with Steven using his new - found power and status to fight against new threats. Others are more character - study - like, delving into his internal struggles and how he copes with being Pink Diamond. You really have to dig in and read a few to find the ones that suit your taste.
In fanfiction, Black Diamond's story can be used to explore themes like redemption and forgiveness. If she was once a tyrant, her journey towards becoming a better being can be a powerful narrative. It can also show how the other characters in the Steven Universe world react to her change, whether they are skeptical or accepting. This can create interesting character dynamics.