Konami just celebrated the first year of their popular card battle game 'Yu-Gi-Oh' duel links and they decided to show their appreciation to the fans by adding loads of bonus content.

Their anniversary features include accessories for customization such as card sleeves and game mats based on series protagonists Yugi Mutoh and Jaden Yuuki, free gems for purchases and tickets for a chance to win rare cards such as Dark Magician, Blue Eyes White Dragon, and Red Eyes Black Dragon.

Additional quests have also been included, with one of them rewarding the players with one of the three powerful God cards, and probably the best obtainable monster cards available — Slifer the Sky Dragon.

Avid 'Yu-Gi-Oh!' players and fans of the anime series can recognize Slifer as the God card that Yugi obtained by defeating Marik's avatar in a duel. The monster appears as a huge red dragon with two mouths and a snake-like body. When summoned, it rises high above the playing field and remains there, as it is too large to occupy a single slot in the player's area.

Being a God card, a player who successfully summons Slifer will enjoy numerous advantages that almost ensures his or her victory. The monster does not have a base attack and defense, but gets 1,000 to both for each card that the player has in hand. The monster also blocks the activation of monster effects and decreases the attack of all opponent's monsters by 2,000 points. Monsters whose attack is reduced to zero by this ability will instantly be destroyed.

The only drawbacks are that it requires three monsters on the player's side to be sacrificed in order to summon the monster, which is no easy feat. Also, If the monster is summoned by other means than sacrificing three monsters, it has to be destroyed by the end of the player's turn.

To obtain the card, the player must defeat Strings, the same puppet-like character Yugi defeated in the anime. He appears in the Duel World as part of the special anniversary missions. Slifer will then be rewarded to the player after his victory.

Also part of the anniversary celebration is the upcoming "Tag Duel" Event coming this late January, which will allow players to pair up against other teams from around the world.