Well, i could say the same thing about God Ki, that Goku have, since is also a energy that not everyone have, and allows the character to sense people that also have God Ki, while that who don't can't sense them.
This is a bit more palatable, though I'm tentatively calling it so, only because I'm more or less curious; wasn't Piccolo able to sense Goku's God Ki despite not possessing God Ki himself? I believe this was the case during
Dragon Ball Super: Broly, where Piccolo telepathically communicates with SSG Goku after he got a beatdown from Broly. I could be misinterpreting though, it's been a while since I've watched the movie proper.
I'm
willing to accept that Goku could sense her if the "limited use" aspect of God Ki and Share Energy were to be equalized. However, I'm hesitant in doing so because of the above question.
Not that It matters much, since Goku dealing with with invisible is not rare to him.
But it is? I don't recall Goku fighting actual
invisible people before, the furthest that could go would potentially be someone significantly faster than him to the point where he can't efficiently spot them or someone with the ability to hide from him in an alternate manner, like lowering their Ki or Hit hiding in a pocket dimension. The most I can remember of
true invisibility was from the original
Dragon Ball with See-Through the Invisible Man, but Goku wasn't participating in the fight, he was just a spectator.
Beyond that, there's the possible problem of him not being able to sense her. If he can't sense her, he will essentially have
zero clue where she is.
Why? He can't sense or see the opponent, why don't see why he would't.
Because if he can't see or sense the opponent, he doesn't even know they're there in the first place. Why would he transform against an enemy who he doesn't even know is existent or present?
Ins't said character way weaker than him trought?
Again, there's the possibility that he doesn't know she's weaker than him because Share Energy go brrr.
Well, he can use his Analytical prediction or teleports to deal this attacks.
Analytical Prediction ain't gonna save him from huge attacks that happen in a split-second right in his face. Teleportation maybe.
However, ranged attacks and AOE aren't necessarily for her to land a hit.
The poison might be a problem if she spams it. Does she?
The Poison is laced into every attack in her arsenal, regardless of what it is; that's what the Disc does. If she uses an attack, it inflicts poison, simple as that. Same case with the Paralysis and Apathy (power null), every attack can inflict it.
Does Neptune just blink in and out of existence with the White Orb?
No, she remains invisible to enemies
until she lands a hit on them, at which point she is entirely visible to them.
Does Goku die from 1 hit due to the aformentioned CC? And can Goku not respond fast enough to hit her with anything and knock her out/incapacitate her, or simply Kiai and knock her out?
Goku doesn't die in one hit, however, he will be hindered so significantly by the Paralysis that he'll be prevented from even doing anything to begin with, and he'll eventually die from the Poison constantly draining away his life. I don't believe Kiai will work in this instance considering he can't move a muscle under Paralysis.
Why is a kilometer sized projectile relevant to a character who can bust universes by farting
Because it's literally happening right in his face with no warning and in a split-second.
But, like I said above already, AOE stuff isn't a necessity to land a hit on Goku. Especially because that immediate >2x speed amp will allow her to swiftly move in and attack. Quite easily, I might add; her swords are huge, and some of them have effects that will make it easier for her to land hits, like Laevateinn shining brighter than the sun, meaning Goku can very easily be blinded by it.
This is also not accounting for the fact that she has a passive effect through "Weaken Enemies" that will slightly neuter Goku in most forms of stats, including speed, as Weaken Enemies affects an enemy's agility.
Even accepting the scenario where Goku
can sense Neptune, her having that speed amp and hindering Goku's own speed (since speed is equalized) will make it much easier for her to land a hit on Goku than it would for Goku to land a hit on her.
I still believe Neptune takes this more often than not.