Kuroyukihime's Brain Burst Avatar is Black Lotus, who had blades for hands which instantly cut any who touch them. She herself was formerly the Black King, although she was driven into hiding after killing the previous Red King while trying to defeat all other kings to reach level 10.
In the Accelerated World, her Brain Burst Avatar's special ability is called Death By Piercing. It is mentioned that her special ability is most likely a direct attack type.