Sol 644, also known as IB-07: SOL 644, is a formidable Armored Core pilot featured in the game Armored Core VI: Fires of Rubicon. Recognized for their association with the mysterious Institute, Sol 644 is one of the advanced IB-series combatants, showcasing exceptional piloting skills and relentless combat tactics. Their presence in the story represents a significant challenge to the player, often acting as a rival or boss character who tests the protagonist’s abilities in high-stakes battles.