First things first, you got to change the location of the battle. I haven't made a location profile for the Ghost Zone yet but it basically allows any non ghost to gain powers similar to a ghost and passively phase through everything including the ghosts so it only helps Saber.
With that said, I'll go over the match with the assumption that they are not in the Ghost Zone.
AP
- Saber: Going off Nicetoderp's comment, Saber is 30 to 40 Gigatons
- Dan > Ancent Ghosts (Together) > Pariah Dark (Crown and Ring) > Vortex = 16 Gigatons
If we go by the numbers Saber is either 1.875 times (Using 30 Gigatons) to 2.5 times (Using 40 Gigatons) stronger than Dan (16 Gigatons) though as I pointed out, Dan has a scaling chain so it likely isn't that large with the exception of the Element Dragon thing Nicetoderp mention.
Lifting Strength
- Saber is Class T
- Dan is Class K
Saber can manhandle if the two engage in a physical grapple.
Intelligence/Skill
Saber is overall more intelligent and skilled going off his profile, especially since Dan doesn't utilize the intelligence he gained from Vlad and takes a more sociopathic destructive approach. That's not to say he isn't capable, he's skilled in the use of his abilities in combat but in hand to hand, he's a brawler.
However, I don't think Saber's overall skill is going to come in to play since Dan isn't likely to engage in any lengthy close combat fight especially when he sees he's out-matched.
Abilities
* Saber:
Saber's Rekka will be effective against Dan since he is evil, plus it gets stronger when heating up. Attack Reflection is also good but Dan can take his own attacks and has multiple was of avoiding them if reflected so I don't see this being to helpful but worth mentioning.
It says he has NPI but the type isn't specified, and Danny Phantom ghosts have multiple types of intangibility so it would be good to get confirmation on which type. His Low-Godly Regeneration Negation and Immortality Negation would allow him to keep Dan from regenerating, however, ghosts have other ways of returning but this is still an inconvenience.
Snce his ESP allows him to sense evil beings and see things others can't, Dan will be unable to preform any sneak attacks. Saber also has other methods to buff his strength and possesses intense heat attacks which ignore durability and I believe are above a ghosts level of heat resistance.
* Dan
Ghost Physiology gives Dan a lot of abilities and while some aren't helpful due to Saber's abilities, there are still some that are helpful. Body Control is useful because Dan actually doesn't use intangibility like that and decides to duplicate himself or open wholes in his body to avoid attacks. This will allow him to dodge simple attacks without worry.
Possession is also a valuable power since Saber doesn't seem to have resistance and Dan's possession is layered. Other than that, most other ghost stuff aren't to useful. However, Dan has his own abilities like Duplication which will allow him to hold the numbers advantage.
Just like Saber, Dan has several ways to amp himself such as the Accelerated Development/Reactive Power level of both Danny and Vlad. Danny's RPL was great enough to allow him to trade blows with the Fright Knight in their battle despite about a minute beforehand, Danny couldn't even make him flinch. He also has statistics amplification with ghost energy which is great enough to tare through those comparable to himself.
Overview/Vote
There was definitely more I could have gone over but I think it's best to keep things short enough to not drag things on.
As for who I'm voting for? I'd say Kamen Rider Saber takes the match pretty handedly.
*
Resoning
Both have multiple ways to amp that allow them to stomp opponents but Saber already starts out stronger and thus would hold the advantage throughout the fight.
Saber's overall intelligence and skill would also allow him to win a close combat confrontation, plus his senses would make any potential sneak attacks useless. And while I'm unsure which NPI Saber has, DP ghosts mostly remain in a physical state when in combat and Dan doesn't utilize his intangibility power anyway so that's not an issue.
Saber can also negate Low-Godly regeneration so he can stop Dan from regenerating, and while Dan's essesne could attempt to Overshadow Saber and reform around him, it's out of character for Dan to use possession and since Saber can sense and see him, he could avoid it without issue.
Dan could potentially outlast (he has infinite darkness) Saber and potentially land a possession with a ton of duplicates but the way Dan fights, that would be something far off from his mind. Plus Saber doesn't seem like he'll run out of stamina any time soon. Shields are also out of character for Dan but even if he did use them, he wouldn't spam them.
So overall, I'd say Saber should win this with some difficulty but handedly.