Blade balls are enemies in Into the Nexus. They are small, floating robots used by the Thugs-4-Less (and the Intergalactic Museum of History for security) as apparent equivalents of Megacorp's PX6 BladeBall. When approaching an enemy they deploy small blades and spin in attempt to harm the enemy.
Ratchet and Clank first encountered them in "Stop Thugs from freeing Vendra Prog", when they attacked the Nebulox Seven alongside the Thugs-4-Less. Some were also present in the Thugs-4-Less outpost on Yerek in "Investigate the Thugs-4-Less outpost", and Ratchet also fought many in the Destructapalooza. In "Find the Dimensionator", Ratchet encountered many more at the museum.
Blade balls are fairly weak swarmer enemies. They pose little threat on their own and can be defeated in one hit with the OmniWrench, or area-of-effect weapons such as the Fusion Grenade or Temporal Repulsor, to destroy them before they are close. However, it is important to eliminate them before they overwhelm. Mr. Zurkon can also help protect Ratchet from them.