It could be incorporated in the environment. For instance, the arena could be set in a sakura - forest - like area. The trees could have special powers or properties. Maybe the sakura trees release a mist that has different effects on the tributes, like making them hallucinate or giving them temporary strength boosts.
One way is to give the Xenomorph - like Pokemon a unique typing. For example, it could be part Dark and part Poison type. This would make its attacks and weaknesses different from regular Pokemon. Another way is to have it with an ability that is related to its Xenomorph nature, like being able to move quickly through vents or small spaces, similar to how Xenomorphs do in their original lore. You could also make its evolution method really strange, like it evolves when it 'infects' a certain number of other Pokemon.
Well, in a Hunger Games fanfiction, love can be a driving force for a character's actions. If they love football, they might use the teamwork and strategy from football in the Games. For example, they could form alliances like football teams do. Their love for another character could also give them the motivation to fight hard, similar to how they would fight hard in a football match.
Imagine a region in the Pokemon world where there is a festival related to diapering Pokemon. Trainers from all over come to show off their best - decorated Pokemon diapers or compete in diaper - changing races. This would be a really creative and fun way to incorporate the concept. It could also be a way for different trainers to bond and share their experiences with taking care of their Pokemon in this aspect. Also, there could be special rewards for the winners, like rare Pokemon items or new types of Pokemon diapers that have unique abilities.
A really creative approach would be to rewrite the backstories of RWBY characters with Naruto elements. Imagine Ruby Rose being trained by a ninja in her childhood, which influenced her to become a huntress. This would add a whole new layer to her character. And then, you could have Naruto characters' goals align with the RWBY characters' goals, like fighting for justice and peace in both worlds, which would lead to some great team - up stories.
The boarding school's architecture can be used. For example, the dormitories could be like the districts in the Hunger Games, and students from different dormitories are pitted against each other. The cafeteria could be a central gathering place for announcements about the 'Games'.
In a Hunger Games fanfic, a tribute could have a special ability related to circadian rhythm. Maybe they can sense the changes in the day - night cycle more acutely than others, allowing them to predict events in the arena. This could make them a target for other tributes while also giving them an edge in survival.
Rue could be the key to a rebellion in a fanfiction. After her death in the original story, her spirit could inspire the other districts. So in this fanfiction, she doesn't die. Instead, she unites the tributes from different districts against the Capitol. Her small and innocent appearance could be a disguise for her strong will and leadership skills.
One way is to have a character obsessed with gloss. For example, a Capitol citizen who is always looking for the shiniest things. This character could play a role in the fanfic by either helping or hindering the main characters. Maybe they provide the tributes with some 'glossy' items that turn out to be useful in the arena.
An alpha lord could be incorporated as a time - traveler. He comes from an era long before Harry Potter's time and has knowledge of forgotten spells and magic. He could use this knowledge to change the course of events in the current wizarding world, for example, preventing certain dark events from happening or enhancing the power of the good side.
He could be incorporated as a visiting star from another dimension. His presence causes a stir among the ponies, who are both fascinated and inspired by his music and moves. The ponies might learn new ways to express themselves from him.