AkumaMoe Helper - Helps download mangas from akuma.moe

animemoehelper.user.js

// ==UserScript==
// @name         AkumaMoe Helper
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  Helps download mangas from akuma.moe
// @author       Nuark
// @connect      s1.akuma.moe
// @match        https://*akuma.moe/*
// @require      https://cdnjs.cloudflare.com/ajax/libs/jszip/3.2.0/jszip.min.js
// @require      https://cdnjs.cloudflare.com/ajax/libs/FileSaver.js/1.3.8/FileSaver.min.js
// @grant        GM_xmlhttpRequest
// @grant        GM_download
// @run-at       document-end
// ==/UserScript==

(function() {
    'use strict';
    let w = unsafeWindow;
    let jq = w.$;

    let blobholder = {
        init: function(filename, details, maxcount, caller) {
            this.filename = filename;
            this.details = details;
            this.maxcount = maxcount;
            this.caller = caller;
        },
        blobarray: [],
        currcount: 0,
        addBlob: function(blob) {
            this.blobarray.push(blob);
            this.currcount++;
            console.log("blob insertion dispatched", blob, this.currcount, this.maxcount);
            if (this.currcount === this.maxcount) {
                this.callback();
                this.caller.text("Serializing...");
                console.log("calling serialization", blob, this.currcount, this.maxcount);
            }
        },
        callback: function() {
            let zip = new JSZip();
            zip.file("description.txt", this.details);
            let img = zip.folder("images");
            this.blobarray.forEach(file => {
                img.file(file[0], file[1]);
            });
            zip.generateAsync({type:"blob"}).then(function(content) {
                saveAs(content, blobholder.filename);
                blobholder.caller.toggleClass("btn-info").toggleClass("btn-success");
                blobholder.caller.text("Done");
            });
        }
    }

    w.zxc = async function (caller) {
        caller = jq(caller);
        let todo = w.pag.cnt;
        let tpl = "{origin}{pathname}/{page}".replace(/(\{origin\})/, location.origin).replace(/(\{pathname\})/, location.pathname);
        blobholder.init(jq(".entry-title").text(), "", todo, caller);

        caller.text(`Pages: ${todo}`);

        for (let i = 1; i <= todo; i++) {
            caller.text(`Fetching ${i} of ${todo}...`);
            let page_response = await fetch(tpl.replace(/(\{page\})/, i));
            let html = await page_response.text();
            let div = jq("<div>").html(html.replace(/(script)/g, "scr").replace(/(link)/g, "lnk"))[0];
            let link = div.querySelector("#image-container > img").src;
            GM_xmlhttpRequest({
                method: "GET",
                url: link,
                synchronous: true,
                responseType: "blob",
                onload: function (response) {
                    let title = response.finalUrl .split("/").pop();;
                    let blob = response.response;
                    blobholder.addBlob([title, blob]);
                }
            });
        }
    }

    function init() { //TODO: location.pathname detection
        let new_btn = jq("#start").clone();
        new_btn.id = "download";
        new_btn.text("Download");
        new_btn.attr("href", "#download");
        new_btn.attr("title", "Download");
        new_btn.toggleClass("btn-primary").toggleClass("btn-info");
        new_btn.attr("onclick", "window.zxc(this)");
        jq("#start").parent().append(new_btn);
    }

    init();
})();

Sorry for the late reply, I'm currently sick, and I'm barely recovering
I was able to download the mangas I wanted to, but they took a long time
The first one is 1587 pages long, so it took it about 1015 mins to Fetch the images, and about 1.30 hours to finish the Serializing
The second one is 1945 pages long, so it took it about 1520 mins to Fetch the images, and about 4 hours to finish the Serializing

It seems to that akuma .moe is having some issue, because right now is down for me, the entire website

Still, thanks for this amazing script, even tho it took an extensive amount of time I was able to download what I wanted!

Glad it helped you, @Markuzkiller