Okay, you guys suck.
Ares: Not a match I have a terrible amount of experience with. He can outpace DS in damage very easily, though in general it takes just knowing Ares' tricks rather than anything special about DS. He can teleport on a read against low shots for a combo, and he's one of the characters who can more effectively neutralize DS's interactable advantage. Teleports are unsafe and can be countered on reaction, so it's always a bit of a gamble for both players, though a good read favors Ares more. He has reasonable zoning tools to make DS not too gunshot happy, and you have to watch out for MB fireball, which is damned fast and does a lot of damage, as well as his trait sword and axe being able to cover a lot of space. Wakeup teleport provides some options against DS's oki, but again, a bad read will get Ares comboed. Faking teleport by triggering invisibility is largely useless for Ares in this match, because he'll more likely than not just wind up getting shot for his trouble.
5-5 match, IMO.
Now, back to Aquaman, so we can have something to add to the first post of this thread.
4-6 in Aquaman's favor.
Deathstroke is outdamaged by Aquaman, particularly because Aquaman can escape DS's main grounded mixups using trait, making him more dependent on f3 to bounce, or block strings if he can get them. Aquaman has more range in the neutral game, and has an effective punish going up to slightly under 3/4 screen on low shots. He can also trait out of quick shots for a check on block with From the Deep, though this does require good reactions. From the Deep is punishable at any range by quick shots, making it bad to do randomly, and trident throw can be reacted against with low shots at a distance, though most Aquaman players won't use it anyways.
While it's hard to jump on him in the neutral game due to his superb d2, Aquaman is one of Deathstroke's easier targets for the flying ninja and for cornered f3 mixups, and his answers against grounded oki aren't as swell as many characters too, provided his trait isn't ready. It's hard to put him off balance, but if you ever do get a knockdown and start doing setups, it can be hard for him to regain his footing.
You either want to be as far away from Aquaman as possible, or standing on his face repeatedly doing setups on him. Midscreen, he's going to win.
Thoughts, revisions, anything? I want something I can tag a mod with to put up on the first page.