There were four distinctive sonic booms as Marcius and his three opponents blurred from their positions.
After reaching the realm of True Lord, the strength, speed, durability, and energy of a cultivator had gone beyond a certain point and had become incredibly powerful. Despite both him and his foes moving at a speed at which naked eyes could not perceive their movements, Marcius remained focused and able to react to all of his opponent's attacks.
But if someone below the realm of a True Lord were to witness the current fight, they would not be able to see anything except blurred movements, sparks flying around from the clashes between different weapons, and the dust and footsteps that echoed through the chamber. In addition, they might be able to hear the sonic booms and loud sounds of metal produced from the fight. But that was it.