Yeah, I see him as far more of an antagonist/ villain-esque character than a 'good guy'.
Even if we put aside how he was playing a sympathetic antagonistic role during picture perfect and the 'rescue Aoi' arc, since it mixed nice qualities (he is trying to save nene cause he loves her so so much) and also bad qualities (his love is very selfish and he is willing to destroy the lives of other people for his goal, regardless if Nene approve of or not.) he have been shady since day one.
Let's talk about his job! His very important job as a school mystery.
We are told being a school mystery means being a shield for the Near Shore. A pillar of protection
And the mysteries are aware of that. It is their duty.
Hanako is also aware of that, he is their lider it would be weird if he wasn't aware of the importance of their roles.
And what is the first thing we see hanako do? Go out of his way to destroy yorishiros. Not a hint of doubt to be seem.
Let's go group! Yorishiro destruction time!!
Yes he said "I am destroying the yorishiros because there is a spy!" but by process of elimination (we got the flashback of every single school mystery except No.1 who are constantly shown to be agaist this yorishiro destruction plain, to the point of rewinding the whole world), Hanako is the spy.
We even got his motives recently:
Regardless if his wish is noble and he want Nene to live, his actions weakened a barrier between worlds, which can put many many people in danger (girls like Sumire used to be sacrificed to keep the worlds separated so you know is a big deal)
It can be debated that doing all that to save his love is heroic but you asked my opinion and well, that is far more of a tragic villain to me than a hero.
We could say "God is manipulating Hanako into doing this!" because that storyline is so convoluted Aidairo could throw any dumb plot twist my way and i wouldn't bat an eye (full bias disclaimer: the 'god' storyline or the 'thing that possessed tsukasa' storyline is the one that least interest me) but even if he is being manipulated... I would still consider Hanako an antagonist.
Like, take the new timeline.
This is clearly not the og amane, he was possessed and sold his soul to the house.
But it is heavily implied that it was his choices that let him here.
Regardless if the choice was selfless at the time (he seem to have been a very sweet man in Tsuchigomori's flashback), it doesn't change all the bad that he have caused AND IS CURRENTLY CAUSING the people that he killed and their families. It doesn't change that this barely human possessed murderer is who he is now. Yes he was a good guy before but he isn't anymore.
So he would be a very tragic villain but still a villain.