Danny doesn't have any Accelerated Development that support him jumping from 8-C to 2-C in the middle of a fight so no, he wouldn't be able to catch up. He'd start at 2-C and there's nothing in the show to suggest he'd grow stronger mid-fight, at least not anything remotely comparable to Goku's Reactive Evolution/Powerups..
He wouldn't start off with it instantly sure, but he wouldn't need to. He can outlast Danny Phantom easily (and there's a chance he'd do it for practice since Phantom's a strong opponent). And while Danny does have some Reactive Evolution, his A.D. makes literally no mention of the insane 'feat' you guys are citing about him becoming 2-C. To say Danny even jumps to 2-C based off that fight is pretty silly when Danny's 2-C rating comes from Danny himself. Danny didn't become two billion times stronger in the middle of that fight.
So your outright ignoring accepted info... ok. Danny's 2-C comes from when he grew in power against the Fright Knight...
On his Powers and Abilities...
Reactive Evolution (Despite
admitting he couldn't fly as fast as Tucker Phantom, during their later battle he became fast enough to
keep ahead of a more powerful version of Tucker.
[4] In his battle with the Fright Knight, he was incapable of even making him flinch with his attack, but later in thier fight became strong enough to trade blows with him and stop his attack.[5] Despite having an
intense prolong struggle against Sidney Poindexter attempt to Overshadow him, Danny
easily manages to overpower and reverse the possession when Sidney tried a second time.
[3] It is also shown later in the series, Danny's
future self became
uneffected by the Specter Deflector and removed it
despite it visibly working on him moments ago.
[6] And when Danny was about to be destroyed by future versions of his enemies,
he gained the Ghostly Wail which his future self stated he did not gain until ten years later
[6]),
Accelerated Development (Passive & Training; Abilities. Danny has shown to naturally develop his abilities,
[4] and increase their effectiveness through training in less than a year, compared to Vlad Plasmius, who stated himself that it required years to develop and learn how to use the same abilities
[7])
On his AP...
At least
Multi-City Block level+ (
Made a crater of
this size in the first episode of the series.
[1] Later grew powerful enough to
fight evenly with an amped
Ember McLain, who at the time was more powerful than when she
overpowered him the first time they fought
[27]), up to
Low Multiverse level (
In his battle with the Fright Knight, he grew powerful enough to knock him back and trade blows with him, despite being incapable of even making him flinch early in their fight[5][36 Universes])
This match up is Danny at 8-A, who Can evolve to 2-C. Danny outright jumped to 2-C in that fight, he has consistent feats throughout the series that show his power grows in several of his fights. I even made a thread on those respectively. Danny gained a move he wouldn't gain until 10 years in the future simple because he was about to be killed by his future enimes, he's shown to gain power and resistances in combat as well.
If your going to say something is false, I suggest you do your research first because that's what's accepted. If you disagree then you need to make a thread because as it stands, Danny has Reactive Evolution and Accelerated Development via feats. The Graphic Novel even shows his emotional drives can massively buff his power as he was weak and his Powers were fading yet after gaining a new drive his power shot up to his future self (fused with Clockwork). He's gained abilities in far shorter time than people far smarter and stronger than him so yes he has reactive evolution and accelerated development that is shown to give him massive boosts. I don't plan on going in circles here.
Swatting him away, even from afar is what I believe is well within Goku's capabilities (see above), although I can't find any gif that would suggest Danny could possess Goku even on-hit. On another note, I browsed the Danny Phantom wiki (which is listed as a source for 'detailed information' on the wiki) and it says that
humans with strong willpower are resistant to being possessed if forced to do something against their will. If that's the case then Danny's possession wouldn't work at all. Though this is probably not likely.
I'd advise you not to take all information from the Danny Phantom wiki when they don't accept all of what we accept (it may be listed as a source but that's for a general take on the series characters and episodes, not battling information) and just because you don't find it there doesn't mean it doesn't exist. The first time Danny's possession
activated, it happened when he placed his hands on Dash's back and you can literally see the possession trigger the shock on his face as he's pulled in and was shocked to see he was in Dash's body, so yes, when Danny activates his possession (
which he does before touching the individual after the first ever time with Dash) and they make contact it will forcefully pull him into Goku's body even if Danny for some reason changed his mind.
As for the willpower thing, that happened one time when Vlad
attempted and successed to overshadow Jack, who didn't stop the possession, he simply could talk breifly to let Maddie know that his will was being overpowered by a ghosts. Heck even later in the series a weaker shadow duplicate could overshadowed Jack without resistance (Season 3, "Eye for an Eye"). But Danny himself
has no issue overshadowing his Jack and left him with no memory of the event unlike Vlad. Danny's possession is outright shown to be better and I even posted a
link showing that Danny's possession is layered and it's explained on the
Ghost Physiology (Danny Phantom) that it affects the target on multiple levels. Danny outright
left mental suggestions in people's minds to make them agree to something and never speak of things again (Season 2, "Reality Trip").
So no, Goku's supernatural willpower that hasn't been shown to counter layered possession that affects the body (on a molecular level), the mind (subconscious), and the spirit isn't stopping Danny's possession.
