The show's strength is in its relationship arcs both with its heroes and villains. It explores the ups and downs of friendship, the gain and loss of true love, and the bond between families. When Sailor Moon makes viewers swoon or cry, it's earned due to its sincere characters and timely backstory revelations.
Prince Endymion was abducted and brainwashed by Queen Beryl, forcing him to attack Sailor Moon with black roses. Sailor Moon called him back to his former self by showing him the star locket he gave her when they were in love on the moon. Mamoru dropped his sword, refusing to follow Beryl's orders any longer. Beryl decided to kill Sailor Moon and hurled a rock pillar at her.
At the last moment, Prince Endymion threw a rose and shattered the stone pillar, saving Sailor Moon. Beryl is injured by Mamoru's rose and Mamoru shielded Sailor Moon with his body from the stone shards.