From Bulbapedia, the community-driven Pokémon encyclopedia.
Power Cottonweed is the name of the deck used by Yuka Furusawa, the Junior Division Champion in the 2010 World Championships. It is one of the four 2010 World Championships Decks, released in November 2010. Each deck comes packaged with a 2010 World Championships Booklet. Each card features a silver border, Furusawa's signature, and limited edition 2010 World Championships back. None of the cards are tournament legal.
Yuka Furusawa's impressive deck gave her many options to winning! Once Pokémon Collector and Claydol have loaded up the Bench, Jumpluff's Mass Attack can really cause some damage! Add in Bebe's Search and Pokémon Communication to find those Evolutions and Unown R for more damage with Mass Attack and a little extra drawing power, and you can see why Yuka's deck made her a Champion!