The main characters could include Naruto, who is known for his strong will and his ability to grow in power. Broly, a powerful Saiyan, could be there. His raw power and his somewhat wild nature would make for an interesting dynamic. Aquaman from the Justice League would be a main character. His control over the sea and his trident would be very useful in different scenarios. And Green Lantern could also be one of the main characters. His power ring could create all kinds of constructs to help the group in battles.