I'll give you Sophitia, Kilik and Taki on account that the three of them... aren't really central plot characters in that game, just ex-mains. I personally think the only one Dante actually has a chance against is Sophitia, because its entirely possible her divine protection doesn't work when faced with a half-angel.
Kilik's powers are centered around Yin and Yang. Dante falls on both extremes with no real middle. Thus, he'll probably lose. Kali-Yuga is made to purify weapons, anyway, and given that its capable of purifying both the Soul weapons, it probably doesn't distinguish by alignment, so I'd say he actually has an advantage. That fight may just turn into a Rebellion vs Kali-Yuga brawl.
Taki's powers are centered around demon slaying. Dante is half-devil. Do the math, it'd be a brawl at best.
Nightmare I think would probably win, but it'd be close if he lost. Nightmare is still very powerful in Soul Calibur 3, and I would say arguably to the point he's actually either caught up or surpassed his 2 self. given he can take the characters who have defeated him before on his way to the citadel.
Dante verses Siegfried ends with Siegfried's win. Something to keep in mind is that during Soul Calibur 3 he actually has Soul Edge and Soul Calibur on him, and this wouldn't be the first time he's drawn either weapon in desperation. Or the last, for that matter. Siegfried would win on virtue of Siegrfried being desperate enough to draw what would be the lesser of two evils, given that Dante is pretty clearly using light/dark weapons himself.
Though I think he'd win with a regular sword. Up till that annoying mess of Soul Calibur 5, Siegfried/Nightmare the First was fairly consistently the most powerful character in the series or very high on the list, depending on your game.
Bonus: Night Terror. Dante loses. Hands down. Fighting the guy is completely non-canon, but a full power Soul Edge is implied to be well beyond the characters as they currently stand, as the last time the Soul Edge was whole Sophitia had the backing of a god to destroy it, and there are arguments as to why Cervantes wasn't a great host in the first place.
"Ware wa Sanger Sombold. Aku o Tatsu Tsurugi Nagi!" The last thing Evil hears before it is Cleaved in two.