The healing treasure that Kai had requested was naturally for Nana, because even after reaching the 1st Echelon Rank, he somehow felt uneasy when it came to curing her.
Even though he believed he could heal anything, as the skill's description said, he had a hunch that Nana's disability had something more than meets the eye.
Kai actually detected a little chilling energy that's almost impossible to detect, as Kai even barely detected it when he pinched her cheeks before. He just had a hunch that he needed an enormous amount of mana for him to be able to cure her using his healing skill.
Even though it was just a hunch, it was better to be prepared fully. That's why he wanted to ask for a high-level healing treasure just in case he couldn't heal here even after reaching the 1st Echelon Rank.
"A healing treasure? Is that person being poisoned or something? How strong is the person you're talking about?" Princess Sylvia asked.