Since the 'bleqch' part is unclear, in Naruto crossovers often there is a theme of cooperation. Characters from Naruto and the other series (assuming it's a Bleach - type crossover) have to work together to face a common enemy. Also, there can be a theme of self - discovery. As the characters are in a new and different world, they might learn more about themselves and their own limits.
I'm not that familiar with a 'bleqch' Naruto crossover. However, Naruto crossovers in general are super fun. For example, some crossovers might involve Naruto characters getting the powers of Bleach characters or vice versa. You could also check out Archive of Our Own (AO3) as they have a great collection of fanfiction. Just type in 'Naruto Bleach crossover' and see what you can find. There might be some really creative stories out there.
Friendship is a very common theme. Since it's about Naruto and his friends in a crossover, it often shows how their bonds are strengthened or tested in the new situations. For example, they might have to rely on each other more than ever.
One common theme is self - discovery. When Naruto is female in these crossovers, she often has to rediscover herself in a new world or situation. For example, in a crossover with the DC universe, she has to figure out how her powers work in a world full of superheroes and villains.
One common theme is power comparison. Fans like to see how Ichigo's spiritual powers stack up against Naruto's chakra - based powers. Another theme is friendship. They often write about Ichigo and Naruto becoming fast friends and learning from each other.
Another theme is the cultural exchange. The shinobi culture from Naruto, with its clans and loyalty, and the courtly culture of Camelot from Merlin. Characters from both sides learn about each other's values, which can lead to character growth and interesting storylines.
One common theme is power combination. For example, when Naruto is crossed over with another series, the story might explore how his chakra and ninja techniques can be combined with the powers from the other universe. This often leads to some really creative and powerful new abilities.
One common theme is the exploration of different relationships. Since it's a harem concept, Naruto has multiple romantic or close relationships with characters from different crossovers. Another theme is the power - up. As he interacts with different characters from other universes, he often gains new abilities or knowledge.
One common theme is the clash of different powers. Sonic has his super speed and acrobatic abilities, while Naruto has his chakra - based ninja techniques. So in many crossovers, they have to find a way to combine their powers to defeat a common enemy.
Power corruption is a common theme. As Naruto turns 'evil', his newfound power often goes to his head, leading to him making morally questionable decisions. For example, in some crossovers, he might use his powers to dominate others instead of protect them.
One common theme is the fish - out - of - water experience. Since Naruto is from his own ninja world, being a student in a new and different setting makes him stand out. He has to adapt to new rules, cultures, and ways of learning.