Gold

His theme

Gold is a heartless Card-Jitsu Power fighter that lives in Antarctica. He is the son of Oak and does not like anything other than winning, never accepting defeat. After defeat, he just says "Weaklings under pressure try harder. To bad next time there won't be any weakness shown.". He then walks of yelling at his Card-Jitsu creature.

Background
It is revealed after E-114 accidentally tripped him and made him drop his backpack, he saw his name and journal. He got a good background on him because of this:

He was born in a base of Team Spaceship. His father Oak treated him badly giving him no toys and scolded him every time he showed weakness, saying that a son of Team Spaceship should not be the least bit weak. He was usually left with Atom who tortured him as bad as his father. This caused him to grow up with extreme fear of weakness.

He one day was in training to become a member of the team when his father came and yelled at him for rubbing his aching flippers when he scaled the mountain. He saw the perfect opportunity to escape and slid down the mountain and ran off for Treewood City. He looked in a small dojo there where Gary was staying showing off state of the art Card-Jitsu Power cards to the Sensei. A trainer came in and chose one for his Gift Card. While the scientist had tea with the Sensei, he broke the window and stole one.

He ran very fast to a town where E-114 just so happened to be passing by and he tripped over his foot, dropping his backpack. He panicked and noticed E-114 had read his information card and journal, took them back and ran again.

Now the rest here comes from information from the trainer, Mac:

Gold fled to Freezeland where the police gave up. He heard there was a arena there, and entered to battle. The leader lost to him and his very powerful Chico. He took the badge and took off when he saw E-114 come in.

More coming soon...

Involvement
Gold now roams Antarctica, facing arenas an battling trainers. While he may not be the nicest penguin in the world, he is said to treat his Card-Jitsu creature with love occasionally, but he scolds himself afterwords.

Trivia

 * He is a parody of Silver from Pokemon