Composed by Yoko Shimomura, The 13th Struggle first appeared as the battle theme for Organization XIII in Kingdom Hearts II, released in 2005. The group of Nobodies served as the game's main antagonists, and their encounters needed music that felt both elegant and threatening, which is why this track became closely tied to their identity. It later returned in other Kingdom Hearts titles and on official soundtracks, helping it reach fans beyond the original game. Online, it spread through gameplay videos, edits and soundboards, where it remains a shorthand for a stylish, high-stakes confrontation.