Hi, so I'm looking for manga where the protagonist is a human at start and becomes different species afterwards or something else as long as he is not human anymore. No virus that gives special powers type please.
it can happen at the beginning or middle of the series, anytime really as long as it's not at the end.
I'd prefer a male protagonist.

The only ones I know Rosario + Vampire and Immortal Regis.

any recommendations are welcome, thanks

High-School DxD (Novel) - male protagonist turn from human to devil. There's manga and anime version, but I recommend the light novel version.

Ajin
Verdant lord
Pupa
Sugar Dark: Umerareta Yami to Shoujo
Kouya ni Kemono Doukokusu
Yaotsukumo
Mushi to medama to teddy bear
Donten ni warau (though its only one of three mains, not the mc)
Me and the devil blues
Night of the succubus mature content warning
Ayashi no ceres
Vampire knight-though i do not advise, its very twilight-ish
Magic-not the mc that changes species, but they do change in a way.
Takeru - opera susanoh sword of the devil
Ao no fuuin
No.6
Global garden
D.Grayman
Owari no seraph
Shuumatsu no laughter
Violinist of Hameln - Shchelkunchik
Blue exorcist
Japan tengu party illustrated
Diabolo
Mephisto
Black rock shooter - innocent soul sort of...
Rakia mature content warning
Terra formars-genetics not virus, but its still kind of super powers, so up to you.
Variante
Dorohedoro
Tanabata no kuni
Claymore
Shingeki no kyojin
Zombie loan
King of thorn
Raiders

I starred the recommended one

Major..the transformation is the main topic
Dawn - Tsumetai Te
Higanbana no Saku Yoru ni Human to youkai
Kaibutsu Oujo* human to er..undead
Mahou Tsukai no Neko human to magical cat
World Embryo
Antimagia human to demon and he is a king. Well, good for when you are bored.
Boku to Majo no Jikan
Cerberus*
Naqua-den
Sengoku Youko* Human who wished to be youkai and Youkai who wished to be human.

Monogatari (Novel)* is a light novel, but especially Kizumonogatari. Human to Vampire, quite different than usual one.


Minor...not delved deep
Übel Blatt warning mature content
Pandora Hearts it's not until at the very end around ch70 or so. Not telling who either, since it will be spoiler.

Kurogane
Kurozuka lot of gore. It's also not explicity told what he becomes.
Campione! questionable, he becomes kind of a god.

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What I like in Trivial Pursuit style. Pick your category: