Creating the mb_adv - Part 1

Sep 09, 2026

Intro

If you've ever tried shiny hunting Wishmaker Jirachi through official methods, you know that it's a very slow and difficult hunt.

You either have to replay the entire tutorial every reset, or save corrupt. The worst part, in my opinion, is being tethered to a Gamecube any time you want to shiny hunt Jirachi.

Let's fix that!

How it works

The Colosseum Bonus Disc doesn't actually generate the Jirachi; it instead sends a program to your GBA, where it is generated and put in your party.

There are a few checks in this program that makes sure your GBA is actually connected to a Gamecube, but luckily, Zaksabeast already created a patch which removes these checks.

Note: This project is not endorsed by Zaksabeast.

By using this patch, we can send the same program to the GBA ourselves!

Why did I make this?

Zaksabeast also created firmware for the Raspberry Pi Pico to send this program to the GBA over a link cable. However, the example hardware setup he suggested was a bit.. janky.

It required cutting a third party GBC link cable in half, stripping each wire inside, and soldering each wire to a Pi Pico. This isn't very easy or accessible for most people, so I've decided to create my own PCB!

Here's my friend using a prototype version of it!

I need your feedback!

I have two designs for the mb_adv at the moment.

mb_adv v0.3a

Pros:

  • ~$20 USD
  • Pretty small (1x1.6in, aka 25x40mm)
  • USB-C

Cons:

  • Will be damaged if you use plug it into a GBA with a GB/GBC cartridge
  • Could potentially damage something if plugged into the GBA and a computer/phone at the same time

mb_adv v0.3b

Pros:

  • Shouldn't damage anything

Cons:

  • ~$30 USD
  • Pretty long (1x4in, aka 25x100mm)
  • Micro-USB

Which version of mb_adv would you prefer? Please let me know with through this interest check form!

Update (9/13/26): Since the results were pretty split, I made a new version with the best features from both v0.3a and v0.3b. Check it out here!

Coming soon...

Now that we can shiny hunt Jirachi without being tethered to a Gamecube, I'll show you how you can extend this setup to shiny hunt Jirachi without needing to save corrupt or replay the tutorial!