Captain Britain! He’s like Captain America. . .with a staff instead of a shield. . . and you know. . .Imperialism. Well that might be how he started but he’s come a long way since then. Captain Britain was one of the first Marvel UK character to be properly tied to the main Marvel Universe. He’s been a solo hero through much of it, but he’s probably better know for his work with MI-13 and Excalibur.
It gives him an interesting dynamic. In a lot of ways, his relationships define him. He’s got strong ties to his wife Meagan, his sister Psylocke, and to Roma and the Captain Britain Corps. Contrasting that, he’s often found that he needs to get the job done by himself. Whether this is due to his responsibilities as defender of the multiverse or the weight of his own power fluctuates with the characters current mindset (which also plays into his power levels). It should prove an interesting dynamic paired with Marvel’s affiliation mechanic.
You can read more about Captain Britain on the Marvel Wiki.