Filler, it's only show him being summoned and then parting.
Hidan is locked and i think kishimoto forgot about his character after all.
His fight with the team again.
He left with Sasori parting words.
"I'm not a bad person after all" and in the end he was seemed as a victim of the manipulation of the mist.
Zetsu is just a living being and he was never human or something that can be compared to a human being.
Yeah but it turned out to be something different.
They will die but will be redeemed also for Orochimaru.
Even for Kabuto he drawed his whole background to show him like a victim just to be redeemed and give him a place to come back.
I haven't even watched the anime until that point. The last time we saw Kimimaro in the manga he was in the process of attacking a samurai before his soul was removed.
That doesn't negate the fact that he is a villain who never reformed.
There was no reformation of Kakuzu even during his fight and if IIRC the last time we even saw him was when he was restrained and talking to Darui. By that point he was still "evil". He even made a suggestive statement claiming that "it" (the fight) wasn't over yet.
What parting words? He was berating Sasori and telling him not to listen to Kankuro when the two of them last spoke. Later on when his soul is about to be removed we hear him threatening to explode and kill everyone if Kankuro doesn't release him. Does that sound like someone who's reformed?
That doesn't make Kisame a "good guy". It just makes him a tragic, idealistic villain who sought what he believes to be a better world. He was still working for a terrorist organization and he still threatened to kill and/or mutilate shinobi for reasons as trivial as them annoying him. We might as well refer to Tobi and Pain as "good guys" if the designation of "bad guy" is limited only to those with a one dimensional personality and motives.
Zetsu has sentience and he is capable of expressing sensations such as pain. He's basically a plant monster with the capacity to think like a human but I'll grant you that he's not really on the same level of being as other Akatsuki members.
Kabuto is a unique case because his situation was brought about by Konoha and plus he wasn't really a significant figurehead for Akatsuki and what they stand for like Tobi and Madara are. Although I do think he should be punished. It probably won't happen though given the circumstances of his past and present situation. Orochimaru doesn't really have that sort of leverage for himself. He's one of the most evil beings in the Narutoverse and having him return to Konoha as if nothing happened would be even worse than Sasuke returning. Plus more than likely his present demeanor is just a facade to keep Sasuke from attacking him. That's the entire purpose behind him helping Sasuke. If he tries to fight now he'll be killed without hesitation. Oro is likely waiting to gather some more abilities before going after Sasuke.