I'm not entirely sure specifically as it's not a widely known mainstream title. It could potentially be a fan - created crossover story that combines elements from 'Attack on Titan' with some other source named 'ttian'. But without more context, it's hard to say exactly.
You could try searching on some popular fanfiction websites like Archive of Our Own or FanFiction.net. Just type in the exact title 'attack on ttian crossover fanfic' in their search bars.
One common theme is loyalty. Pieck is often depicted as being loyal to her comrades and her cause. Another theme is sacrifice, as she is in a situation where she may have to give up a lot for the greater good.
Well, 'The Tale of Pieck' is a really interesting 'attack on titan pieck fanfic'. It delves deep into her character, showing her relationships with other characters in a more detailed way. For example, it shows her interactions with Porco and how they support each other. There's also 'Pieck's Secret Mission' where she embarks on a covert operation that is full of twists and turns.
I'm not sure which specific 'Pieck Finger fanfic' is the best. You can try looking on some popular fanfiction websites like Archive of Our Own. There might be a variety of stories there.
Often, there might be themes related to her abilities and how she uses them in different situations. For example, in battle or when facing challenges. Another theme could be her backstory and how it shapes her personality and actions in the fan - created stories.
A common theme is loyalty. Given their comradeship in the series, fanfictions often explore how their loyalty to each other extends beyond just being fellow soldiers. Another theme could be sacrifice, as they are in a dangerous world where they might have to sacrifice for one another.
Love and romance are also likely themes. Writers may depict the development of romantic feelings between Yelena and Pieck. This could involve slow - burn romances where they gradually realize their feelings for each other, or perhaps more fast - paced love stories where they fall in love quickly due to some extraordinary circumstances. There could also be themes of sacrifice, where one of them is willing to sacrifice something for the other in the context of their relationship.