Shen Sui really didn't expect that the opponent would be so headstrong, actually proceeding despite Anna's effect.
Although midway, Yuan Youxin was already a bit in over his head, but that was because he was too greedy, aiming for an FTK result.
In a Life Card Duel, a new card can indeed result in a "First Encounter Kill," because during the duel, the opponent can't check the effects of your cards like in previous card games—this is why some professional players, even after achieving fame, still continuously play Life Cards in the Soul Card World.
Yuan Youxin might have spent too long bullying amateurs in tournaments, not even having basic awareness to guard against traps.
Since Shen Sui dared to send Anna to the graveyard in front of this Burst Expansion Card Set, he was certainly not afraid of being counter-killed by utilizing Anna's effect.
After Yuan Youxin summoned Luo Fen'gu, Shen Sui's hand also reached fifteen cards.