M.int

The IV and EV system in Gen II is the same as in Gen I.
The “mordern” EV and IV system that’s being used today was introduced in Gen III with Ruby and Sapphire.

yt-dlp (the most up-to-date version of youtube-dl) has hundreds of supported websites. The generic downloader can download from unsupported websites most of the time and if that doesn’t work you just paste in the m3u8 file as seen in my answer.

That sometimes works, but you might need to add some arguments like here --add-header "Referer: https://vidmoly.to/"

Yeah, just stumbled across that.
Video DownloadHelper a blast from the past. Haven’t used that for more than a decade (I discovered youtube-dl and never looked back). I didn’t look further in my testing, only promted me for a license when a wanted to download only audio, which seemed kinda scummy since there isn’t even a pure audio source on the website as far as I can tell.

According to the waterfox documentation you should just be able to install the extension from addons.mozilla.

If you want to use this addon on this website you still need the CoApp installed separately.

I just tried it and this does work but you need to install their CoApp, which seems to basically just an ffmpeg wrapper.

Okay, this was harder than anticipated. Maybe someone can find an easier solution:

Go to the video you want to download, open the DevTools in your browser (F12 in Firefox), go to Network (you might need to reload the page), play the video. In the search bar under Network type in .m3u8. You’ll get a file likely named master.m3u8. Right-click on it ‘Copy value’ than ‘Copy url’. Paste this in the following yt-dlp command:

yt-dlp \
  --add-header "Referer: https://vidmoly.to/" \
  "https://paste-url-here.to/master.m3u8"

This should download the video.
If you want the subtitles, search for .vtt instead (you might need to select the desired subtitles in the player first). You can directly open the subtile file and download it.

I really hope someone can give you an easier solution.
Don’t hesitate to ask further questions!