In this fanfic, Loki's character can be developed by giving him a backstory related to his role as an agent. Maybe he was forced into this role by some threat to Asgard. This would add depth to his character. Also, his interactions with the different Avengers, like Iron Man's sarcasm rubbing off on him, can change his personality over time. He could go from being a self - centered trickster to someone who cares about the team's well - being.
Well, in this graphic novel, Loki has to carry out various missions in Asgard. He's constantly dealing with the politics and power plays there. His character is complex, and the story explores his relationships with other Asgardian characters. For example, his interactions with Thor are always interesting, as they have a love - hate relationship. There are also elements of magic and mystery throughout the story.
A plot could involve Loki using his agent skills to manipulate the Avengers into a false sense of security. He then reveals a master plan that involves using their own powers against them to take over Earth. But in the process, he starts to have second thoughts as he gets to know the Avengers better and forms unexpected friendships. For example, his interactions with Black Widow could lead to him seeing the value in human relationships.
There could be. A lot of fans like to create crossovers between different shows they love. To find a 'Coulson is Lucifer' fanfic, you could try searching with specific tags on fanfic platforms. Some fanfic writers are really creative and might have come up with an interesting story combining these two characters.