no, there is no cheat codes for shadow pokemon. perhaps in hacks there is
The Shadow Pikachu card has 999 HP.
There is unfortunately no such thing as shadow pikachu if someone has one it is fake
You can't get a Shadow Pikachu on Ruby/Sapphire/Emerald.
you can find cheat codes for fire emblem at CCC.com (cheat code central)
the same as pikachu's static and lightningrod
you can find cheat codes for fire emblem at CCC.com (cheat code central)
There is no shadow pikachu in either one of those games.
Shadow Lugia is only available in Pokémon XD: Gale of Darkness and is fought as part of the storyline. You're able to get a Master Ball prior to fighting Shadow Lugia, so catching it shouldn't be a problem and needs no cheat code.
at the computer
you don't need a a code, a wild pikachu may hold one 5% of the time
No, there are no cheat codes in the game.
There is indeed a shadow Pikachu. Many people in the world have drawn this incredible Pokémon in many different poses.