Definitely Coulson. He has such a rich backstory and his relationship with both the Agents of Shield and the Avengers (in an indirect way) is very interesting. His resurrection in Agents of Shield also provides a lot of potential for fanfiction. You could explore how he copes with being brought back to life and his new purpose.
I think Fitz and Simmons from Agents of Shield are great choices. Their relationship is so endearing and their scientific knowledge is a unique aspect. In fanfiction, they could be the ones to develop new technology that helps both the Agents of Shield and the Avengers. For example, they could create a device that enhances communication between the two teams during a big mission, and the story could revolve around the development and implementation of this device.
In Avengers fanfiction, Phil Coulson is often considered one of the best Shield agents. He is highly dedicated, intelligent, and has a deep understanding of the Avengers. Another great one could be Maria Hill. She is tough, strategic, and can handle high - pressure situations well. And then there's Clint Barton, who combines his excellent archery skills with his Shield agent training.
Definitely Captain America and Agent Coulson. Captain America represents the old - school heroism of the Avengers and Coulson is the heart and soul of Agents of Shield. Their different leadership styles and moral compasses would create a great dynamic. They could learn from each other, like Coulson teaching Cap about modern technology and Cap teaching Coulson about the values of the past.
Loki could be a great focus in a fanfiction involving both. He has a history with the Avengers, but his wily and unpredictable nature could lead to some interesting interactions with the Agents of Shield. He could be playing his own game, pretending to help both groups while actually having his own agenda. It would be fun to write about how the Agents and the Avengers try to figure out his true motives and keep him in check.
Thor is another popular Avenger in fanfiction. His god - like powers and his fish - out - - of - water moments on Earth are fun to explore. And from Agents of Shield, Fitz and Simmons are beloved for their scientific genius and their endearing friendship that often gets tested in different fan - made scenarios.
Skye (Daisy Johnson) is also very popular. Her journey from a hacker to a powerful Inhuman is fascinating. Fanfiction often delves deeper into her powers and her role in both Shield and in relation to the Avengers. She has a complex personality which gives a lot of room for creative writing.
I think Daisy Johnson would be really interesting. She has her unique powers and a complex backstory from her time in SHIELD. In a crossover, she could interact with the likes of Thor. Maybe she could learn some new ways to control her powers from him, as he has experience with his own godly powers. And she could also show the Avengers her skills in combat and stealth that she learned in SHIELD. It would be fascinating to see how she holds her own among the super - powerful Avengers.
Definitely Captain America. His strong sense of justice and leadership makes him a great character to build a story around. Also, Agent Coulson is really popular. Fans love his dry humor and his ability to hold his own against super - powered individuals. And then there's Black Widow. Her mysterious past and badass fighting skills are always interesting to explore in fanfiction.
I think Loki can be a really interesting character to focus on in Avengers sitcom fanfiction. He has that mischievous nature that can stir up all kinds of trouble in a sitcom environment. His illusions and tricks could be used for comical purposes, like making the other Avengers think there are hordes of tiny monsters attacking them. Scarlet Witch could also be great. Her powers are a bit unpredictable, and in a sitcom, this could lead to some really funny and unexpected events. Maybe she accidentally turns all the furniture in the compound into animals one day while trying to practice her powers.
I think Weiss from RWBY could be really interesting to focus on. Her strict upbringing and powerful semblance would contrast well with the more chaotic nature of the Agents of Mayhem. From the Agents of Mayhem, Brick would be a good character. His brute strength and no - nonsense attitude could lead to some humorous and action - packed scenes when paired with the RWBY characters.
Well, Tony Stark would probably be quite cocky around the Agents of Shield at first. He might make sarcastic remarks about their technology compared to his. But then he'd realize they have some unique skills and knowledge. Steve Rogers, on the other hand, would be more respectful and interested in their mission. He'd see them as comrades in the fight against evil. Natasha Romanoff might find some kindred spirits among the female agents of Shield like May. They could share their combat experiences and spy techniques.