Championship decks are a great way to get a taste of playing with premium cards without the price tag, but they're not worth anything, so they're not a target for collectors
All of the Main Deck Melffys can be brought out from the hand in the End Phase and all have unique effects to bounce themselves and provide some benefit when the opponent Summons a monster or attacks
LAVD-ENL13 Lunalight Scarlet Tiger Level 5 DARK Beast-Warrior Effect Monster ATK 1900 DEF 1500 If you activate a Lunalight monsters effect (except during the Damage Step): You can Special Summon this card from your hand, then if you activated this effect during the turn your opponent activated a card or effect, you can add 1 Polymerization from your Deck or GY to your hand
Legend of Blue Eyes White Dragon Curse of Dragon Foil Super Rare 2002 Yu-Gi-Oh
Cubic Karma X SPELL Continuous When this card is activated: You can target 1 "Cubic" monster you control, except "Vijam the Cubic Seed"
If you choose the first and third modes, and destroying the creature ends an exile until effect (such as that of Lunarch Inquisitors), the creature will return to the battlefield before you put +1/+1 counters on creatures