Pink Diamond is the true, albeit, unintentional antagonist on Steven Universe. (Also, antagonists don't necessarily equal villains) I've thought this for a loooong time now, but after watching the Steven Universe movie, I'm set in stone on that. Thousands of gems have been shattered or forever scarred by her self-indulgent decisions, because she it literally incapable of viewing the world outside the scope of her own self interests.

Inspiration for the template: RoboCatRC
   • GRRRLS | Animation meme - Eclipsa (St...  
Original Meme: Kapti Lps
Music Box version by R3 Music Box:    • GRRRLS/AViVA [Music Box]  

Song is GRRRLS by AViVa