Kunzite was setting a new scheme to steal the energy of humans. In this scheme, it was a masquerade ball where their energy would get stolen whenever the youma danced with them. He had plans in place for if the Sailor guardians show up, he even had plans on if the human plan got involved.

But you...

Little human you... he didn’t plan on you showing up.

Kunzite looked at you from across the ballroom. A human, defenseless against someone like him but something about you was different.