animelon-subtitle-downloader.user.js

// ==UserScript==
// @name         animelon-subtitle-downloader
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  download animelon subtitles
// @author       mescyn#5794
// @match        https://animelon.com/video/*
// @grant        unsafeWindow
// @grant        GM_registerMenuCommand
// @require     https://cdn.jsdelivr.net/npm/file-saver-es@2.0.5/dist/FileSaver.min.js
// ==/UserScript==

GM_registerMenuCommand("Download Subtitles", AnimelonSubtitleDownloader);

// downloads all subtitle options (english, hiragana, katakana, japanese romaji)
function AnimelonSubtitleDownloader()
{
    var subtitles = angular.element(dialogueHistoryLists).scope().$parent.subtitlesArray;

    for (var i = 0; i < subtitles.length; i++)
    {
        var s = subtitles[i].assString;
        var decodedSubtitles = CryptoJS.AES.decrypt(s.substring(8,s.length-5),s.substring(0,8).split("").reverse().join("")).toString(CryptoJS.enc.Utf8).replace(/undefined/g,"");
        var blob = new Blob([decodedSubtitles], {type: "text/plain;charset=utf-8"});
        var subtitle_name = "animelon_" + document.URL.split('/').reverse()[0] + '_' + subtitles[i].language + '.ass';
        saveAs(blob, subtitle_name);
    }
}

How to use this script

You need the tampermonkey chrome extension. You can install the userscript by hitting raw on the gist, and you'll be prompted to install it. Once installed while viewing a video, you can right click and then Tamper Monkey > anime-subtitle-downloader > Download subtitles (or just click on the tampermonkey icon and hit download subtitles from there, either way).

It does download all the subtitles for the show (normal japanese, hiragana, katakana, and english).