Mystic Mine can be synergic with Ojama Duo and prevent your opponents monster effects and keep you on the control of the game
This should hopefully be enough to end games, even if you haven't had the best start.
[21] World Duel Carnival Preliminaries[edit] At the beginning of the World Duel Carnival, he met Yuma, who was panicking because he didn't have a Heart Piece
The rest of the cards are Hope for Escape , Zero Gardna , Swift Scarecrow , Threatening Roar , Waboku , and One Day of Peace , all attainable from repeatedly surrendering to the Seeker Duelist Challenge
You can banish 1 "Nemeses" monster from your hand or deck
Other players may have different reasons to keep a large collection of cards, for instance I know a player who tries to collect one of every card thats printed including one of every promo card