"How to trick Pokebank into thinking your Gen 1 Mew is the "legit" one from the event via arbitrary code execution with 8F."

Warning: This method can be long and complicated if you're unexperienced with Gen 1 glitches. Actually it's pretty long either way. Be very careful. The "8F" item will crash your game if you use it without very specific setups.There are probably easier ways to get a legit Mew, like posting on /r/PokemonPlaza or turning off your 3DS halfway through my method and screaming in frustration about redditors who give you overly complicated solutions to getting a Mew.So the only way to transfer Mew is to have a Mew with OT GF and ID 22796. So we will be setting up arbitrary code execution to change the OT and TID of your first Pokemon to the "legit" ones. It's easy!Step 1: Obtain 8F.You need this thing to do arbitrary code execution. You just do. I wish you didn't.First we must acquire a stack of 255x X Specials. I know how weird this sounds. Remember Missingno. adds to our items though, so this is easy. Encounter Missingno. with the method of your choice. Easiest options are the Old Man glitch or Trainer Fly with a Special stat of 31, 32, 50, 52, 56, 61, 62, 63, 67, 68, 69, 79, 80, 81, 86, 87, 94, 95, 115, 121, 122, 127, 134, 135, 137, 140, 146, 156, 159, 160, 161, 162, 172, 174, 175 or 181 (Thanks Bulbapedia). If you don't know how to do this, just look it up, many great tutorials exist on Youtube.Before you encounter Missingno., make sure 1x X Special is in the 6th slot of your bag. Encountering Missingno. ads +128 to this, giving you 129 X Specials. Now while in battle, USE two X Specials. Now you have 127. Now catch Missingno. This will add +128 again, giving you 255x X Specials.Now set up your bag as follows: 1x random item, 1x random item, 255x X Special, 1x random item. The rest doesn't matter.Toss the first 2 random items. Your 255x X Specials will duplicate. You will now have 3 stacks of them. This is normal.Continue tossing stacks of 255x X Specials until you only have access to 2 items (every time you toss a stack your bag will shrink by 1 slot, but it's OK, we'll fix it later).Toss 253x of the first 255x X Specials, then swap item 1 with item 2, then swap them back. You will now have 0x X Specials in Slot 1, and item underflow is active.Go to the very right edge of Celadon, one step from exiting the route. Toss 255x X Specials from the stack of 0 (Scroll one number away from 0) and then switch the remaining 1x X Special with the Nugget in the 35th position of the bag.Walk 5 steps right, 5 steps down, 20 and steps right, then open the item menu to see 8F. Switch this item with your first item, then walk to any Pokemart and buy items until your bag is back to normal, working order.Yay now we have 8F. Wasn't that easy. DO NOT USE THIS ITEM WITHOUT SPECIFIC SETUPS OR YOUR GAME WILL CRASH.Step 2: Setting everything else up.That's the delicate part out of the way. Now for the tedious part where we cancel Pidgey Evolutions for 50+ levels (or, as /u/avodrok points out, just use a combination of Trainer Fly and the experience underflow glitch to get a Pidgey at level 1 instantly bring it to level 100 and skip this).Your party must be set up in a specific way for this to work. The reason is that 8F executes garbage code which you're redirecting around to force it to do what you want sorta like a Gameshark... Other people can explain it better.Set up your party as follows: 1. Mew, 2. Pidgey with 233 CURRENT HP (Max HP doesn't matter), 3. Parasect, 4. Onix, 5. Tentacool, 6. Arbok (obtain it via the Mew Glitch if on Red). That Pidgey is a bitch. I hate it.Set up your bag as follows: 1. 8F, 2. Any item x89, 3. Dire Hit x58, 4. Iron x37, 5. X Accuracy x119, 6. Water Stone x62, 7. Burn Heal x50, 8. Poké Ball x43, 9. Antidote x43, 10. Protein x62, 11. PP Up x60, 12. Ice Heal x50, 13. Lemonade x134, 14. Great Ball x50, 15. Fresh Water x34 16. TM01 x[any #]For the 119x X Accuracy and the 134x Lemonade, use Missingno. to obtain over 99 items in a stack. Remember that Missingno. ads +128 to your item stack, so plan accordingly.What's going to happen is our specific party runs 8F to our bag, where we have more freedom, and our specific bag setup executes code that we want. You can do practically anything with this method. I'm serious. It's absurd.Step 3: Do it.Use 8F.That's it. Your Mew should be "legit" now.Credit goes to Glitch City Laboratories for this method, if you want to learn more about 8F and what it can do (along with the Yellow equivalent, ws m) check out http://ift.tt/2k4WPcE for the setup described in this thread goes to http://ift.tt/2jgmvyu! Don't blame me when you get addicted to glitches and inevitably find yourself slowly inputting data bit by bit by running through Rt 1 using ws m to write coordinates as bits for your shakily written code. I wish I was joking.EDIT: Minor fixes.EDIT 2: Ok I figured out how to edit the DVs of the Mew to be perfect. I'll need to mess around with it to figure out how to set them up so the Mew will always be shiny, but for now...Put the Mew as the first Pokemon in your current box.Set up your party as follows: Pidgey with 233 HP, Parasect, Onix, Tentacool, Kangaskhan.Items as follows: Any item (any #), 8F, Lemonade x[*], X Acc x178/177**, Carbox x218, Pokeball x119, Fresh Water x201.* Number of Lemonade: I'm not 100% sure how this works. If you do 255x Lemonades it will set the DV to F (which is 15). If you do 254x I'm fairly certain (though this is untested) that it'll set it to 14. If this DOES NOT WORK, please let me know and I'll try to look into it further.** 178x sets Speed and Special DVs, 177x sets Attack and Defense.According to Serebii on Shiny Pokemon transferred from Gen I to bank, "Shiny - Based on the IVs of the Pokémon in Generation 1: 10 in Attack, Special & Speed and Defense a multiple of 2 = Shiny"So therefore... Set your Lemonade to 250x and then use 8F, drop 1 X Acc so you have 177x, then use 8F again and it should make it shiny on transfer. This is untested though. Someone testing this would be appreciated, as I don't have a 3DS with both Pokebank and R/B atm.All credit still goes to Glitch City Laboratories. via /r/pokemon http://ift.tt/2jfmhaP