The Armored Core (AC) piloted by Hustler One and the main antagonist of Armored Core and Armored Core: Master of Arena, often spelled "Nine-Ball". It is considered one of the strongest and most iconic ACs, due to its status in-game.
During the events of Armored Core and Masters of Arena it is revealed there are multiple Nine-balls and Hustler One is actually an AI controlling them, created by and protects Raven's Nest system.
Nine-Ball=Seraph is an upgraded version in Master of Arena and most common depiction. Nine-Ball Onyx, referred to as Nine-Ball or Baby's Breath in-game, is a recreation of the original Nine-Ball in Nine Breaker and Nexus.
Nine-ball is a recurring element in the series and appears or is referenced in most games. References include, but not limited to White Glint's pilot and V.IV Rusty being ranked 9th in their respective game or HAL 826's coloration and the shape of its head in VI: Fires of Rubicon.
It is sometimes associated with Cirno from Touhou due to its status as the "strongest" AC and connection to the number 9 among fans of both series. Nineball=Cirno is a fusion of the two, generally depicted as Cirno with Nine-ball's color scheme and boosters.
