The significance could be related to her heritage. Perhaps Erza discovers that she has a long - lost family connection, and the tattoo by Nuarto is a traditional mark of that family. It could then be a source of new spells or abilities that are specific to her family's magic, which she can use to help Fairy Tail in their adventures.
One possible fanfiction could be about Erza Scarlet getting a special tattoo by Nuarto that gives her some unique power in the Fairy Tail universe. Maybe it's a tattoo that has a connection to her past or unlocks a hidden magic ability.
Perhaps in the fanfiction, Aquarius Nuarto is sent on a special mission by the Fairy Tail guild. This mission could be to retrieve a magical artifact that has been lost underwater. Along the way, she meets new characters, some of whom become her allies and others her enemies. She uses her water - based magic skills and her wits to complete the mission.
One of her major achievements was helping to defeat the dark guild Phantom Lord. Her strength in battle was crucial in protecting Fairy Tail. Another significant thing was her role in the Tower of Heaven arc. By facing her past and the people who once enslaved her, she not only freed herself but also the other slaves there. It was a huge step in her character development as well as a great victory for justice.
Erza Scarlet is a very strong and complex character in Fairy Tail. She is known for her strict and disciplined nature. She has a tragic backstory where she was enslaved at a young age on the Tower of Heaven. But she overcame that and became one of the most powerful mages in the guild. She is often seen leading the charge in battles and is respected by all her guildmates for her strength and leadership.
In some fanfictions, Erza's father could be a powerful mage who was lost in a great battle against dark forces. His absence then becomes a driving force for Erza's growth and her determination to fight evil.
Well, their child could be a symbol of hope in the fanfiction. Since Erza and Jellal have such complex pasts, the child might bring a new era of peace between different factions. For example, the child could have the power to bridge the gap between the Magic Council and the independent guilds. Also, the child's appearance might be a mix of Erza's red hair and Jellal's mysterious eyes, making it stand out in the Fairy Tail world.
In some fanfictions where Erza dies, it could lead to a dark and tragic turn for the Fairy Tail guild. Her death might cause the other members to question their strength and purpose. For example, Natsu might be consumed by a desire for vengeance against the ones who caused her death.
Perhaps the fanfiction could start with Jellal proposing to Erza in a very romantic way, like on top of a mountain overlooking a beautiful sunset. Then, the preparations for the wedding could be filled with some comical moments, like Natsu trying to help with the decorations but making a mess. After they get married, they might go on a honeymoon to a far - off land, where they encounter some old enemies who are now reformed and they all work together to solve a new mystery in that land. The fanfiction could end with them coming back to Fairy Tail stronger than ever and ready to face whatever comes next as a married couple.
One possible fanfiction could be about Erza having to face Siegrain in a battle where Siegrain is being controlled by some dark magic. Erza, with her strong will and powerful magic, tries to break the control on Siegrain while also fighting his attacks. This could show her internal struggle between her feelings for the person Siegrain once was and her duty to stop the danger he now poses.
It could involve Erza facing challenges in the Edolas version of Fairy Tail. Maybe she has to deal with different versions of her friends or new magical threats specific to that realm.