Grey stood in the middle of four figures that were sent flying. He didn't make another move, he could already tell that all four of them were dead.
The man in the Pseudo-Sovereign stage thought at least one or two of the people would survive, but Grey didn't attack with the intent of letting any of them go.
When Grey appeared, he unleashed his shocking killing intent which froze the unsuspecting men before using the fusion orb. He didn't only use it, but he attacked with a series of attacks that went off at the same time. The fusion orb was the strongest and it covered the rest of the attacks. This was the reason the Pseudo-Sovereign didn't notice it.
He heaved a sigh of relief when the Pseudo-Sovereign didn't go after Conor who left as soon as he used the talisman. It was clear that the man was still in shock at Grey's sudden attack.