So like, I personally think the starting distance is rigged for Dante. Dante already doesn't like to stay in long range for long, even with his guns out he closes the distance on opponents, and his acrobacy would allow him to close the gap as Billy seems to lack actual examples of his own acrobacy (Having Hyper-Momentum there doesn't actually do much). The Starting distance also makes one of Billy's ability just not work since it needs at least 6 meters of distance
In terms of Gun Skills, there is not a lot about it on Billy's profile itself but tbf, not a lot on Dante's either. Either way, I'm not led to believe there would be an immense advantage to one or the other. Dante
shot a Demon in the head while said Demon had a hostage and Dante was moving, showing no real concern he would actually miss his target,
can shoot small targets without looking, hit
Lady's shoes while she is moving and while he tries to not kill her and
hitting a small target while wall running. He should also be decently comparable to her as well,
which includes more shots that hit small targets (
One when she was driving a car)
Billy's Status Effect Inducement seems to only happen when he does damage to opponents, which is off set both by the AP advantage and via Regeneration, so those likely would never come into play. Billy's Damage Boosts are weirdly written and have no actual link for me to read how they are, so I'll try to break down them a bit:
Roaming Gunslinger increases his counter damage, no idea what counter damage is but it might happen here;
Starlight Hero seems to work by shooting someone 10 times in a row, stacks 5 times (Which I think it reads as needing to shoot someone 50 times) and it lasts until he is knocked back, this might happen but I would be surprised if Billy can have the 5 stack on Dante. Dante has no shockwave generation but I assume any simple hit can just knock Billy of his feet.
Steady Shot increases damage by staying still or until he gets knocked back, so probably not happening.
Starlight Engine Replica will just not happen due to the starting distance and Dante constantly getting closer
Regardless of how Roaming Gunslinger and Starlight Hero work, they won't have multiple stacks or make up the ~3.2x AP advantage Dante has. Getting a few videos on how Billy's Danmaku works would be neat but I can infer a bit of them on the text. Starlight Sunction doesn't seem very threatening while I can see Billy's Ultimate doing some work on Dante, don't know how Ultimate works on ZZZ, but I can't imagine Billy has access to it 100% of the time.
Billy's skills in combat seem to have been praised by a World Champion boxer, but Dante has a range advantage with his Sword and he's also decently skilled himself so I don't think it matters a lot. For Dante himself, he likely wouldn't be opposed of dispatching Billy, he wouldn't do it ASAP, he would still drag the fight a bit as there is not really a reason for Dante to just go for the kill, but he eventually will. Regen makes the fight harder for Billy as I've stated above adn there is a likely chance Dante will try to disarm Billy's weapon if they pose a serious threat with his Ultimate.
Overall I would give it to Dante more often then not unless Billy has a lot of his most notable stuff not in the profile (But I'm pretty sure by rules they wouldn't factor here since you would need to make a CRT to add said things to profiles since you can't use things that aren't on his profile on a vs match here)
