Ken, infamously nicknamed "The Grim Reaper" and often called Ken the Grim Reaper, once infiltrated Hosuke's circle in female disguise alongside his henchmen, aiming to uncover Sho's weaknesses. He commands loyal minions swathed as mummies. Ken possesses a distinctive, high-pitched, girlish laugh that sometimes punctuates his actions. He later reappeared publicly on television, where he and his mummy-clad forces battled Gen while simultaneously targeted by Team X.