Probably Anakin Skywalker. Given his importance in the Clone Wars, it's likely he would cross paths with Jaina. They might have some intense lightsaber duels or deep conversations about the nature of the Force.
Their relationship could be developed through shared memories. For example, they could both recall their time as students in Dalaran. Flashbacks of their innocent days together, studying magic and having friendly competitions, could bring them closer. This could lead to a rekindling of their old feelings in the present of the fanfiction.
I'm not able to directly recommend specific 'Jaina' fanfics at the moment. But you can start by looking on fanfic platforms like Archive of Our Own. Search for 'Jaina' and then filter the results to find ones that focus on positive aspects such as her heroism, her friendships, or her development as a character.
In fanfic, Jaina Solo is often depicted as a strong - willed and highly skilled character. She is usually shown to be a great Jedi, with her combat skills and Force abilities being emphasized. For example, in some fanfics, she might have epic lightsaber battles against powerful enemies.
Another great Jaina Solo novel is 'Traitor'. This novel really explores her growth as a character, her relationships within the Star Wars galaxy, and her part in the greater galactic events. It's full of action and interesting character developments.
One common theme is her struggle between her Jedi duties and her personal relationships. For example, in many fanfictions, she has to choose between her love for someone and her commitment to the Jedi Order. Another theme is her growth as a Jedi, from a young apprentice to a powerful Jedi Knight.
Jaina in Fantasy Strike is a really interesting character. Her story likely involves her journey in the game's world, which might include her battles, her growth in power, and her interactions with other characters. But without more specific details, it's hard to go into great depth.
Arthas and Jaina were once in love. They grew up together in Lordaeron. Jaina was a powerful mage, and Arthas was a promising paladin. However, Arthas's thirst for power and his fall to the Scourge drove them apart. His actions became dark and cruel, and Jaina could not follow him on that path. Their love was a tragic one, as Arthas was consumed by his inner demons and Jaina was left to grieve for the man he once was.
You can start by looking on Archive of Our Own (AO3). It has a large collection of World of Warcraft fanfiction, including many about Thrall and Jaina. The search function there is quite good, allowing you to filter by tags and ratings.
One great 'thrall and jaina fanfiction' is 'The Bond Beyond Kingdoms'. It delves into their unique relationship and how they might bridge the gap between the Horde and the Alliance in a more personal way. It's full of emotional moments and interesting character development.