Some fanfics also focus on the psychological aspect of their relationship. Reiner and Bertholdt both have complex personalities and backstories. Fanfics might explore how they understand and support each other on a psychological level, perhaps dealing with their inner demons together.
Fanfiction.net is also a great place to look. There are many 'Attack on Titan' fanfics there. Just type in 'Reiner x Bertholdt' in the search bar and browse through the results. However, the quality may vary, so you might need to read a few to find the really good ones.
Both Warcraft and Warhammer Fantasy have their own strengths when it comes to storytelling. Warcraft offers a story that is very much centered around heroism and the fight against great evil. The story arcs of many of its heroes are quite inspiring. On the other hand, Warhammer Fantasy has a more sprawling and detailed world. The stories are often intertwined with the history and mythology of the various races. It's really hard to say which one has a better story. If you like a more heroic - focused and fast - paced story, Warcraft might be better for you. But if you prefer a darker, more complex world with a lot of historical depth, Warhammer Fantasy could be the one.
It's really hard to say. The Young Justice has some really powerful members like Superboy and Miss Martian. But the Titans also have strong characters like Starfire and Cyborg. It could depend on the situation. If it was a battle in an open field, the Titans' more experienced members might have an edge. But if it was a stealth mission - type battle, Young Justice's skills could give them the victory.
Reiner did die in the manga. His death was a result of a series of events and conflicts that had been building up throughout the storyline. It had a major impact on the plot and the other characters.
One idea could be a misunderstanding that leads to a battle between the two teams. Maybe a villain manipulates information so that the Young Justice team believes the Titans are up to no good. Then, as the fight unfolds, they start to realize they've been tricked.
It's really hard to say. In Warhammer 40k, there are extremely powerful Space Marines with advanced technology and psychic powers. However, in Star Wars, the Force gives Jedi and Sith incredible abilities. If it's a large - scale battle, the Imperium of Man in Warhammer 40k has a huge number of troops. But the Star Wars galaxy has the Death Star which can destroy planets. So it depends on the specific scenario written in the fanfic.
In Warhammer 40k, the Emperor is an extremely powerful character. His psychic powers are off the charts and he has a huge influence over the entire Imperium. In a face - off against Star Trek characters in fanfiction, he would be a formidable force. In Star Trek, Q is a very powerful being. He can manipulate reality at will. If Q were to engage with the Emperor, it would be a battle of two extremely powerful entities with different natures. Q's mischievous and almost omnipotent nature against the Emperor's more serious and controlling power would be quite a showdown.