Retrieved August 26, 2021
In this case, both players get to banish cards from each other's graveyard
In fact, the manual explicitly says that "the best way to find what combinations work best is to try them out." This trial-by-error approach means you'll likely lose more than a few duels before you know what combinations of monsters work, and even then, you might not know why they work
In Speed Duel, each player uses a smaller deck of between 20 to 30 cards, with an Extra Deck of up to just five monsters
However, you can also acquire a UR jewel from level up rewards
Its power level is so extreme that its banned everywhere its legal to play, except in Vintage, where it remains restricted to a single copy