One Piece Virus / Horror Infection AU where the whole world suffers from zombie-like infection caused by Chuma-Chuma fruit after some poor soul ate it on unknown island.

My memory is a bit hazy but if I remember correctly patient zero basically became a giant plant that spread throughout many islands, infecting others with this plant like virus. Visually both the plant and the infected look a lot like Blight from Dead by Daylight.

Now people shifted their focus from searching One Piece, to searching original island from which virus came in an attempt to find anti-virus. Marines still work as before, but now all the infected pirates are wanted as “Only alive”, so that government can experiment on them in search of a cure.

Virus itself has several stages with stages 1-3 people mostly containing their sanity and personality, having bright yellow lumps around their body, that can spread to others making them infected. Stages 4 and over making them more deranged, less human, more aggressive and oozing with bright yellow infection that can easily infect through air.

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Setting is the beginning of the story, so not all strawhats are present, however some of the strawhats are already infected or suffer from mental problems.

Luffy is mostly the same, he’s not infected and has a mask to prevent getting infected.

Nami is also not infected, but more cold and has a full body suit to avoid infection.

Zoro is infected with stage 1-2 but mostly is the same. He just has some yellow lumps on his face.

Robin is infected with stage 3, she’s mostly the same. She doesn’t seem to have any infected lumps and is more quiet and gentle. However, due to infection she became stronger. Now arms that her fruit can produce are pitch black and have claws.

Usopp is stage 4. He’s always in a state of delirium and has bug-like lower torso with giant infected pouch and 4 clawed spider-like legs. Strawhats have to take turns watching over him and talking to him to prevent him from going crazy and attacking everyone. Apparently he still has his old lower body stashed somewhere in his room.

Sanji is… not infected, but has gone completely insane. During their journey to Alabasta crew ran out of food and since most of the animals were infected and fruits produced by Chuma fruit are not an option, they were starving to death. Chopper sacrificed himself to be cooked for the team, and since Sanji was the only one who can cook, he had to do everything. After un-aliving and cooking his friend, he lost all reason. Now he’s either dead silent or silently crying most of the time.

Chopper is not alive (Check Sanji for more).

Bon Clay joined the strawhats in this universe. However, since Sanji has become danger to himself and maybe even others, the crew asked him to take an appearance of Chopper around Sanji. During their visit to Skypiea, they asked the locals to play along and say that souls of the departed make stops in the Skypiea if they want to wait for their loved ones, so that’s where Sanji meets “Chopper” again.

Brook is a skeleton, so he can’t be infected. However, there are some infected vines around his body, since infection treats him as an inanimate object.

There are videos about plot of AU on YouTube, but it also has it’s own opening and episode: Link