A main theme of
Steven Universe, according to its creators, is that almost nobody is truly good or truly evil. Antagonists aren't permanent, and are all multi-faceted with a chance of
redemption. The protagonists also have the capacity to become
malicious and harmful. However, they are very unlikely to become largely 'evil' compared to 'evil' characters becoming 'good', making the show lean slightly towards
White and Grey Morality at times.
- The major theme of season 3 is showing that while the Crystal Gems were fighting for a good cause against Homeworld's imperialist conquering, Gems on both sides suffered a lot during the Gem war. Rose Quartz was always implied to have done many questionable things during her time, with Garnet saying out right that she kept many secrets from them. As Bismuth's reappearance in the present day proved, the decisions of a leader are never easy. When Bismuth presented her with a weapon known as the Breaking Point that was capable of shattering Gems, effectively fragmenting their beings into several self-aware pieces that are subjected to A Fate Worse Than Death, Rose wouldn't stand for the thought of shattering as it would taint her belief that all life was worth giving a chance and making them no better than the Diamonds. Bismuth understandably upset seeing her friends broken in battle and having her creation rejected, faught Rose to take back the weapon for herself, forcing Rose to bubble Bismuth who was too dangerous to be set free. Yet she never told any of the Crystal Gems what happened to their friend, making them believe she was lost. For all that, Jasper reveals a few episodes later during one hell of a Villainous Breakdownthat the vicious, uncaring soldier who spared no pity for others came back to Earth to get revenge on Rose for shattering Pink Diamond, an act equivalent to deicide in Homeworld society. As a Ruby and later Garnet confirmed, Rose went against her own morals because she felt it was for the greater good, so that Earth, humanity, the Crystal Gems, and Steven to exist, compromises had to be done. And for all that, the Homeworld Gems who faught in the war are crushed to know that all their sacrifice and centuries of fighting were for nothing. As Greg said back in season 1, "There's no such thing as a good war, Kiddo."