@comeonnow0 His actual personality is rare yes, but that's irrelevant, people like Yamcha are rare but he's still useless. Why is that? Because if we're measuring his personality in usefulness, all that matters are the decisions he makes that effect the story, and those decisions are not that uncommon. They're not super common but it wouldn't be hard to find people that could make them.
As for your second paragraph...I'm starting to think you're actually a child. Him being proved innocent was not by his own actions. We're talking about this thing called 'agency' here. Your conscious decision making. Honoka made -zero- decisions consciously to prove himself innocent. Yes he was innocent because he actually was, but he did -nothing- to prove it. He showed no
agency during that. He just let everyone do their thing and that resulted in him being proven innocent because he was innocent. If anyone else who was innocent was in that situation, it would be the same result, because it was by everyone else's efforts that he was proven innocent. By inverse, if Kagari didn't present all those documentations and speak up, Honoka, would've been found guilty, despite being innocent. Because Honoka didn't -do- anything during the incident, he jsut stood there.
You need to look up what the word 'agency' means, because you have no idea. Also Kagari liking Honoka is not something Honoka did. Because guess what, even if they aren't perfect, it's Kagari's decision if she's obsessed with them. Honoka didn't make that decision for her, and it could still happen if the person wasn't as 'perfect' as Honoka. What you are doing is taking actions and decisions other characters made, and attributing them to Honoka because "Honoka is awesome" or something. But that is more proof than anything that Honoka is actually useless, the fact that you're literally taking other's actions and saying they're Honoka's. The credit for the action goes to who had the agency, who made the decision.
And whether or not he's unique has nothing to do with my evaluation. The reason I talk about him being so easily replacable, is because -Honoka- isn't needed for this story to work. What's needed for the story to progress is "A nice guy that is Evermillion's vessel" Just like Krillin and Yamcha, what is needed is a -role- not the specific character. In contrast you have someone like say Cell, you can't just replace him with high powered bad guy and get the same result. Because the way cell went about doing things went with his developing personality. You specifically needed that arrogance and pride, and Saiyan dickishness that developed when he became perfect Cell in order to get the cell games result.
And as for your motivational speaker example. The motivational speaker is infact replaceable. Because no matter how good they are, they can't make the decision for you. You need -something- to motivate you, it doesn't have to be a specific motivational speaker. Now where this differs from the motivational speaker is, that you're comparing two very different types of 'story'. With teh motivational speaker you're talking about the story of someone being motivated. So of course the motivation is pivitol. However the story here, is actually the narrative of the interactions going on around Evermillion's current host. It's not actually the story of Kagari and Honoka. Yes the Author wants to show us the story of Kagari and Honoka, but the mechanics in their world are not moving because of Kagari and Honoka, in the world of the manga, things are moving because of Evermillion. The two MC's are just pieces moving in Evermillion's life. That's what's brought everything in their direction, Evermillion not Kagari and Honoka. And Honoka himself has done next to nothing to effect that, and the things he has 'done' have been with zero agency.
What you're doing would be like saying that a police officer who is sitting in his car, eating donuts, stopped a lady from getting mugged on the street because he was there. So that police officer was 'useful' to this incident. No he wasn't, firstly he can be replaced with any police officer being there. And the officer didn't actually stop the crime. The crime didn't happen, but that was because the criminal go scared, the officer didn't actually take any conscious action to prevent a crime, it was just
coincidence.