Like her sister, she also has the parasite, Merora attached to her head, this serves as the weakspot. When defeated, Ziyu gives the player a completely unnecessary panty-shot as she falls backwards.
Ziyudee has two primary attacks: Her main attack is to summon a microphone, and proceed to start singing. Apparently tone deaf, these physical music notes act as destructible projectiles and travel towards the player. Her secondary attack is to jump, whilst walking. Care must be taken to not be above the boss in case she does this. In between attacks she will walk the length of the battle arena. In the Saturn/PSX remake, as an additional attack, when she lands after jumping, Penguins will fall from the top of the screen.
Ziyudee can only be damaged whilst she is walking, and is invincible during her attacks. A character with spread or explosion based weapons can sit beside her whilst she is singing and remain unharmed, as her projectiles can not withstand much damage.