I honestly don’t see any means of Hikage’s victory. Neo just has her beat in every category.
For one, Overactive Imagination is just an unstoppable ability/advantage, even without the aid of its Evolution. It can create doubles, render her camouflaged, create illusions, act as a means of defense and evasion (she once used her reduced body mass to avoid an attack she shouldn’t be capable of whilst pretending to be Oscar, meaning it legitimately alters the size of her body or at least creates that effect), etc. And its cost is zero.
You may be thinking, “but Hikage can sense presences-“ That doesn’t work here. Aura, when used by skilled practitioners such as Neo herself, can ALSO sense presences. This is shown in the entrance exam with Ren, again with Ren sensing Tyrian in hiding, and Fox Alistair (one of Team CFVY), can do it too. He even pulls off specific feats such as gauging strength, identifying specific people, and seeing it in color. This is to say, it’s decently thorough. Anyway, Overactive Imagination tricked everyone I just mentioned, and more who while not displaying the ability explicitly, logically should have it via scaling. (Ozpin, Qrow, etc.) It just bypasses those methods of detection for some reason.
So sensing her presence doesn’t work. You’d think poison would help, but not really, as Hush is a perfect defense against her knife play, which is what the poison is restricted to. And unless her knives clip through Aura, (which it won’t, but it will be able to be focused on it for heightened damage, like Yagyū and Katsuragi), they’ll never cut and actually infect her. It also doubles to make her energy blasts meaningless, as do Hush and her illusions.
Not to mention Neo’s whole fighting style works to completely make all contact with her opponent nonexistent. She flows around and redirects foes, using their own capabilities against them while adding her own. This is why the only person to ever toss Neo around like a rag doll is the person with the power of precognitive reflexes. As in, moving before Neo’s able to actually move and counter her before she can even get to utilizing her main strategy.
This puts Hikage on the back foot, and as it works on those stronger than her, would mean that even if Frantic and Frenzy mode were used, it wouldn’t get better at all, and would only serve to dumb down Hikage (from the berserker rage) and burn resources. Not to mention that it creates openings to exploit. Which the other issue—Everything Neo does creates an opening for her to brutally and beautifully smash down on. Her Semblance misdirects perfectly, creating openings, her fighting style redirects perfectly, creating openings, her weapon counters and parries all attacks perfectly, creating openings.
And she’s more than skilled, ruthless, and intelligent to take advantage of those deficiencies in her foe, especially in a way that haughtily allows her to make them look like an utter fool. (See basically all of Yang V Neo.) Then to top it off she has the strength edge.
Really, I can’t conceive a wincon for Hikage here.