How to Shiny hunt unintended Game Corner Pokémon w/item underflow glitch (Part 1: Basic example)
56Notes (what is happening in a nutshell):
For a friend who is a shiny hunter who asked me. I won't reveal their online handle for their privacy.
Yep, the Game Corner gift mon have the (statistical) 1/8192 chance, which has lead to some Shiny hunters getting Shiny Porygon with it. (Even though Generation I Shinies don't officially exist, in Generations I and II DVs control Shininess. The DVs are random. You can check the stats of the Pokémon at a certain level with certain or no stat experience in a certain way to determine whether it is a Shiny when transferred to Generation II (example https://www.youtube.com/watch?v=h_P-abfgll0 )
You can also get a 'Shiny glitch Pokémon', then convert it into a certain Shiny Generation II Pokémon depending on which glitch Pokémon you obtained, see https://glitchcity.wiki/Time_Capsule_exploit#From_Generation_I_to_Generation_II and https://glitchcity.wiki/Abnormal_Pok%C3%A9mon on how to avoid the error message that stops you from trading it in Generation II; the table at Time Capsule exploit#From_Generation_I_to_Generation_II is potentially confusing but if you have any questions feel free to ask. "Trade" for instance is what you'd get when it appears in Generation II.
Here I suddenly get a Game Corner Charmeleon prize ^^. Which should be able to be Shiny, hence the iconic Shiny Charizard is possible.
The shiny hunter asked if you could manipulate any Pokémon; the answer is yes, even without arbitrary code execution (which the example does not use), which lead to me revising the research done by Pokémon glitched speedrunners.
You basically without any technical terms change the text boxes in the map, which can give you glitch lists, also known as glitch Game Corner (lists), which may include unintended Pokémon and/or glitch Pokémon. For a list in Red/Blue (however I'm using Yellow), see https://pastebin.com/bbRJfFzz by luckytyphlosion; who discovered this before me but kept it in mainly speedrunning circles. I can't remember when this was new, but note it actually is relatively old now, just obscure.
In technical terms, you adjust the text pointer table in RAM from the expanded inventory to still point to a Game Corner list. The text ID (i.e. dispenser or NPC you talk to) determines the Game Corner list.
This is usually used to control the lists, not individual entries, unless you can get a RAM glitch Game Corner list.
Note it's a bit technical, but if you want to do this I can teach you if you like question by question ask me anything. ^^
This is my own draft:
https://pastebin.com/44aZiDaE
Hope this video, description or these Pastebins help! ^^