The main characters would be a mix from both sides. From the Gokaigers, we would have Captain Marvelous, who is bold and adventurous. He would be a great counterpart to Kion from the Lion Guard. Kion, with his sense of responsibility and the power of the Roar, would be a central figure. Also, other members of the Gokaigers like Joe Gibken, who is more of a tech - savvy character, could interact with the Lion Guard in interesting ways. For instance, he could help the Lion Guard understand some strange technological threats using his knowledge, while the Lion Guard could teach the Gokaigers about the natural magic and powers in their world.
One possible plot is that the Lion Guard discovers some strange energy signatures that seem out of place in their world. These turn out to be related to the Gokaigers' power sources. As they try to figure out what's going on, the Gokaigers also detect a disruption in the balance of their power. They meet up and find out that a powerful enemy is trying to harness the combined power of both the Gokaigers' ranger powers and the magic of the Lion Guard's world. So, they have to put aside their differences and work together. The Lion Guard can use their natural abilities like Simba's roar, while the Gokaigers can use their mecha and ranger attacks to battle this new threat.
How about including characters from Sailor Moon? It would be really interesting to see the Gokaigers interact with the Sailor Scouts. Maybe they could learn some new strategies from the Scouts' magic-based attacks.
Fuli could be another main character. Her speed and agility could pose a real challenge to Janja. And perhaps in the fanfiction, they could develop an unexpected respect for each other through their encounters.
The main characters are likely to be the members of the Lion Guard.
Kion is often a very popular character. As the leader of the Lion Guard, he has a lot of responsibility and his journey of growing into his leadership role is fascinating. His power of the Roar of the Elders also makes him stand out.
One common theme is friendship. When different characters from various crossovers come together, they often have to learn to trust and be friends. For example, in a crossover with a different animal group, they must work together as friends to achieve a common goal.
For 'the lion guard crossover fanfiction', consider a crossover with 'Zootopia'. The Lion Guard could travel to Zootopia and be amazed by the different animals living together in a city. They might get involved in a mystery in Zootopia, like helping Judy Hopps solve a case that involves some of the African animals. This could lead to interesting interactions between the Lion Guard's more natural and wild ways and the civilized society of Zootopia.
Naruto himself could be one of the main characters. He has a strong sense of justice and loyalty, which would make him a great addition to an honor guard. His ability to inspire others would also be an asset.
Definitely Simba and Pikachu. Simba as the rightful king of the Pride Lands represents leadership and courage. Pikachu, being one of the most popular Pokemon, is full of energy and has a strong sense of loyalty. They could form an unlikely but strong friendship in the crossover.
The main characters would be Naruto, Simba, and Mufasa. Naruto enters the Lion King world and meets Simba. But through some magical or spiritual connection, he also gets to interact with Mufasa's spirit. Mufasa's wisdom combined with Naruto's skills and Simba's leadership would form the core of the story. They would face challenges together, like threats to the Pride Lands or internal power struggles within the animal kingdom.