I actually thought long and hard about how to address Vangeance, whether to go by his given name or his surname, and sorta flipflopped between the two options a lot even while writing his app. And though I originally went by William to stick with standard English conventions, in the end, I feel like it's more true to his presentation in the manga to refer to him with his surname.
Other characters refer to Vangeance almost exclusively by his surname. Of course, for a lot of characters that's true just because he's the Golden Dawn Captain, but it's in contrast to the other captains who are often referred to by their first name (plus honorifics). Going by first name basis is obviously a necessity for characters like Fuegoleon and Nozel who share surnames with a bunch of other characters, but even characters like Charlotte and Rill who have unique surnames are addressed by given name when the captains are talking to each other. The only exceptions seem to be Yami (who goes pretty much exclusively by 'Yami') and Vangeance, who most people address by surname.
The only characters who address him as 'William' seem to be Julius, Patry and, for some reason, Fuegoleon ... ?
Obviously, Julius has known Vangeance since his childhood days, so they share a special bond; Vangeance also refers to Julius as 'Master Julius' instead of 'Wizard King' as a suggestion of some personal intimacy mingled with his tremendous respect and devotion. And he also shares a special bond with Patry, which explains the first-name basis.
I'm not entirely sure why Fuegoleon is on a first-name basis with him, but my guess would be that it's more a reflection of Fuegoleon's character than it is of Vangeance's. Fuegoleon is one of the more compassionate captains, and being one of the elders captains, might feel some level of protectiveness or warmer camaraderie towards the other younger ones. The manga doesn't go into it much, but the anime also portrays him as showing some concern for Vangeance during the Big Reveal, which really just goes to show what a good guy he is. (Sorry Fuegoleon, you didn't deserve the bullshit you got put through.)
Anyway, the bottom line is that Vangeance is probably meant to stay a little mysterious and aloof for most people, and so I stick with going by his surname in most cases. He won't shy away from being called by his given name or anything, but it'll probably feel a bit odd for him. After all, he's practically defined by his position as 'Captain of the Golden Dawn,' with very few people knowing about him as 'William Vangeance, an individual person.'
regarding vangeance's name
Other characters refer to Vangeance almost exclusively by his surname. Of course, for a lot of characters that's true just because he's the Golden Dawn Captain, but it's in contrast to the other captains who are often referred to by their first name (plus honorifics). Going by first name basis is obviously a necessity for characters like Fuegoleon and Nozel who share surnames with a bunch of other characters, but even characters like Charlotte and Rill who have unique surnames are addressed by given name when the captains are talking to each other. The only exceptions seem to be Yami (who goes pretty much exclusively by 'Yami') and Vangeance, who most people address by surname.
The only characters who address him as 'William' seem to be Julius, Patry and, for some reason, Fuegoleon ... ?
Obviously, Julius has known Vangeance since his childhood days, so they share a special bond; Vangeance also refers to Julius as 'Master Julius' instead of 'Wizard King' as a suggestion of some personal intimacy mingled with his tremendous respect and devotion. And he also shares a special bond with Patry, which explains the first-name basis.
I'm not entirely sure why Fuegoleon is on a first-name basis with him, but my guess would be that it's more a reflection of Fuegoleon's character than it is of Vangeance's. Fuegoleon is one of the more compassionate captains, and being one of the elders captains, might feel some level of protectiveness or warmer camaraderie towards the other younger ones. The manga doesn't go into it much, but the anime also portrays him as showing some concern for Vangeance during the Big Reveal, which really just goes to show what a good guy he is. (Sorry Fuegoleon, you didn't deserve the bullshit you got put through.)
Anyway, the bottom line is that Vangeance is probably meant to stay a little mysterious and aloof for most people, and so I stick with going by his surname in most cases. He won't shy away from being called by his given name or anything, but it'll probably feel a bit odd for him. After all, he's practically defined by his position as 'Captain of the Golden Dawn,' with very few people knowing about him as 'William Vangeance, an individual person.'