If you have no cards in hand during your Standby Phase, you can still activate "Card Trader" and draw a card even though you cannot send a card from your hand back into the Deck. (The game seems to assume that the player must have at least 1 card in their hand during their Standby Phase because it immediately follows the Draw Phase, but it is possible to have an empty hand during the Standby Phase if the opponent plays a Trap or Quick-Play Spell that discards the player's card(s) after they draw, or if the player's Draw Phase is skipped with a card effect.)
One of the game's Theme Duel matches is to achieve victory through "Destiny Board" as fast as possible, with the S-Rank being awarded by winning within 5 turns. However, this is (nearly) impossible because "Destiny Board" requires both players' turns to pass in order to place one "Spirit Message" card; normally the minimum possible number of turns needed to win a Duel by "Destiny Board" is 8 (if the player draws it on the first turn and successfully uses it), which is an "A" rank (awarded by winning within 10 turns). The developers seem to have mistaken the turn count as counting only the player's turns, rather than both players' turns together.
A win in 7 turns is possible if the opponent goes first and happens to trigger the player's "Makyura the Destructor" (which is a Forbidden card) on their first turn. With near-ridiculous amounts of luck, a win in 5 turns is possible with three copies of "Gamble", if all three plus "Destiny Board" are drawn on the first turn, the opponent happens to meet their activation conditions, and all three coin flips land as intended. (With even more ridiculous luck, a win in 4 turns is possible if both "Makyura" and 3 copies of "Gamble" are put together. This requires that the player manage to draw into one of their copies of "Gamble" during one of the opponent's turns.)
From a purely theoretical view, the effect of the opponent's "Arcana Force XXI - The World" can take the place of any copies of "Gamble"; however, this card did not exist in the OCG/TCG at the time of this game's release. Contrary to an old TCG ruling, it is not possible to play two copies of "Destiny Board" and have them place "Spirit Message "I"" and "Spirit Message "N"" at once; both copies will be forced to place a copy of "Spirit Message "I"". (The original ruling was due to a translation error and does not exist in the game; had it been allowed, a victory in 5 turns would have been theoretically possible with "Makyura" and no skipped turns, by using an effect(s) to temporarily negate the effect of "Destiny Board", allowing the second copy to be removed from the field without removing any other letters. This translation error was eventually fixed in 2016 with the release of "Dark Sanctuary".)