Those dark markings on Sukuna's hands in 'Jujutsu Kaisen' always hit me like a visual thunderclap — they signify more than just aesthetic menace. On a basic level, those tattoos are a branded symbol of his identity: an ancient, malevolent presence stamped onto flesh. They're tied to his status as the King of Curses and act as shorthand for his historical, almost mythic power. Whenever the lines crawl across skin or flare with cursed energy, you instantly know the rules of the scene have changed.
Digging a bit deeper, I think they represent the way cursed energy flows and the manner in which Sukuna's influence overrides ordinary human agency. They echo tribal or ritualistic tattooing and classical oni imagery, which makes sense given his legendary origins in the series. The markings also emphasize contrast — between Yuji's humanity and Sukuna's ancient cruelty — when Sukuna takes over. In battles, they light up at moments of control, suggesting a link to his technique and willpower rather than being mere decoration.
On a more personal note, I love how non-literal the symbolism is. It’s not explained in a single chapter; instead it accumulates meaning through action, history snippets, and design choices. Those hands tell a story: ownership, primal power, and a kind of aristocratic malice that I can't help but be fascinated by.