I think Gabriel from Ultrakill would make for an interesting crossover. His complex personality and powerful abilities would add a lot to the Murder Drones' world. He could be a force that either helps or hinders the Murder Drones depending on his goals. His presence would also likely stir up a lot of drama among the Murder Drones characters as they try to figure out what his intentions are.
The Minos Prime from Ultrakill could be an exciting crossover character. Minos Prime is a large and imposing figure with great strength. In the Murder Drones world, it could be like a giant among the drones. Its sense of justice might also lead it to try and impose some order on the chaotic world of the Murder Drones, or it could be seen as a threat by some of the more self - serving characters in that world.
One possible plot could be that a character from Ultrakill ends up in the world of Murder Drones. Maybe the Ultrakill character's combat skills are put to the test against the Murder Drones. They could form an uneasy alliance at first, as they both realize they have a common enemy, like a new type of rogue AI that threatens both of their worlds.
Well, you could write a fanfic about a Murder Drone that gets damaged and loses its memory. It then has to figure out who it is and what its purpose is while being helped by a group of Worker Drones. Another interesting idea is a fanfic that explores the emotional side of the Murder Drones more. What if a Murder Drone starts to feel guilt for killing Worker Drones? And a fanfic where the Murder Drones encounter a more advanced form of themselves from the future, and they have to decide whether to follow in their footsteps or find a different path.
Guts would be a very interesting character to crossover. His tough - as - nails attitude and his massive sword would make him stand out in the world of GoT. He has a lot of combat experience and a dark past, which could make for some great interactions with the morally ambiguous characters in GoT.
I think Rock Lee would be really interesting. His extreme dedication to training and his unique fighting style would be a great contrast to the often chaotic and self - serving characters in the GTA world. He could run around the GTA streets, challenging the thugs to combat and trying to uphold his ninja code in a very different and morally ambiguous environment.
The interaction between Yu Narukami from Persona 4 and Makoto Yuki from Persona 3 could be really interesting. Yu is a very calm and perceptive leader, while Makoto has his own sense of leadership. They could share their experiences in leading their respective teams and learn from each other.
I think Kakashi would be a great choice. He's already a very versatile character. If he had Frozone's ice powers, he could combine it with his Lightning Blade technique. He could freeze enemies in place and then finish them off with his lightning - enhanced sword. His intelligence would also make him very creative in using these new powers.
Akira and Minato would be an interesting pairing. Akira, with his leadership skills as the leader of the Phantom Thieves, and Minato, the protagonist of Persona 3, could share their strategies in combat and dealing with the Metaverse. They both have different experiences with their respective groups, so they could learn a lot from each other.
The Arbiter and Thor. Thor is a powerful Asgardian with his hammer and lightning powers, while the Arbiter is a skilled warrior from the Halo universe. They could fight side by side against a common enemy. Their different cultures and fighting styles would make for an exciting combination. Maybe Thor could teach the Arbiter about magic, and the Arbiter could show Thor some unique Covenant combat techniques.
The interaction between Saitama and Levi would be really interesting. Levi is known for his serious and efficient fighting style, while Saitama is super - powerful yet non -chalant. Levi would probably be both intrigued and a bit annoyed by Saitama's laid - back attitude towards the Titans. Saitama, on the other hand, would probably just see Levi as another person in this strange world.
Another interesting pairing could be Kevin from Ben 10 and Byakuya. Kevin has his unique powers related to absorbing and manipulating energy, which could contrast with Byakuya's refined and traditional Soul Reaper skills. They could start off as adversaries, perhaps misunderstanding each other's motives, but then come to respect and work together as they realize they are facing a common threat that requires both their skillsets to overcome.