Battle Tower Lati@s glitch - Capture a Battle Tower Pokémon (Ruby/Sapphire)

Read the description for more information:
The Battle Tower Lati@s glitch is a major Generation III glitch that isn't that well known about yet. It was reported in Japanese Ruby, but actually works in both US releases of Ruby and Sapphire. It does not work in Pokémon Emerald.

The glitch allows you to capture a Battle Tower Pokémon, such as level 100 Linoone, Hariyama, Dustox, etc. The Pokémon can be nicknamed and will not turn into a Bad Egg.

The Battle Tower Lati@s glitch was documented in 2012 in Japanese by an anonymous 2ch user. http://kohada.2ch.net/test/read.cgi/p... volty706 mirrored the conversation on their blog, calling it the "wandering glitch" (Japanese: 徘徊バグ). http://86530.diarynote.jp/20130129204...

To perform this glitch, the player must lose (or win?) against a Battle Tower Trainer, and then encounter Latios or Latias without encountering another Pokémon in between (very important).

The player should defeat the Latios/Latias, and this will cause a "PkMn Trainer" with a blank name with a team based on the Battle Tower Trainer you lost against to send one of two of their Pokémon (the game thinks that you KOd one of them).

This Pokémon will flee like Latios/Latias, so it is a good idea to use Mean Look or Spider Web against them if you cannot catch one with a Master Ball. If that Pokémon is defeated, the Trainer will send out another one of their Pokémon, which can be captured and can flee like the first Pokémon after Latios/Latias faints.

If the Trainer is defeated, no victory text will appear. The player can gain experience from the Battle Tower Pokémon if a Pokémon participated that is below level 100, and if that Pokémon gains experience, the wild Pokémon victory music may play and stick, even if the battle hasn't ended yet.

The origin of a Pokémon obtained with the Battle Tower Lati@s glitch is stated to be "BATTLE TOWER (met)".

On August 1, 2014, G- Mizuka uploaded a video showing the glitch in Japanese Pokémon Ruby.    • ポケモンルビー　ラティオスバグ Pokemon Ruby Latios Glitch  

On July 17, 2014, SailorJupiter sent me a message with some great news that the Latios glitch in fact works for US English Ruby. I couldn't find the time to test it, but today I decided to test it on emulator, and verified it on an English Sapphire in addition to an English Ruby.

A few major questions and answers (many thanks to NicoDuran):
http://pastebin.com/Q6Lp5enG

Elite Four Lati@s glitch (Related glitch, not shown):
   • ポケモンルビー　ダメタマゴをチート無しで捕まえる Pokemon Ruby How ...  

In English and Japanese Ruby (likely English Sapphire as well), if the player loses against an Elite Four member and then encounters Latios, they can KO it and have the Elite Four member send out another Pokémon.

Unfortunately all of Sidney's Pokémon became Bad Eggs with Pokérus. However, you can exploit this to spread Pokérus by battling with the Bad Egg in the party, because after the battle ends the Pokérus has a chance to spread (even though the original affected Pokémon was a Bad Egg).

Note: I tried losing against a regular Trainer in English Ruby (I haven't tried an Elite Four member yet. I will test this today) and unfortunately couldn't get a regular Trainer Lati@s glitch (KOing it ended the battle as normal).

Save files of beaten Pokémon Ruby and Sapphire with roaming Latios and Latias available:

Ruby: https://mega.nz/#!E51lEYAL!2gdB7jbUl-...
Sapphire: https://mega.nz/#!V8tkFIjD!8IwPTNdqMB...

I played FractalFusion and GoddessMaria's Ruby (http://tasvideos.org/3186S.html) and Sapphire (http://tasvideos.org/1629S.html) TASes in order to quickly beat the games.