Looking at the dragon in front of her, Shiro narrowed her eyes.
Dragons have one of the strongest vitalities in the world, just second to demons. Especially someone like Madison. For her to 'heal' him to death, she had to find a way to force the dragon to tap into this vitality which wasn't easy.
After all, their natural healing was already tremendous.
When tapping into a person's vitality, they need a catalyst to stimulate this change, something that forces them beyond their limits. A berserk skill would be classified as such as it taps into a person's vitality, unleashing power beyond their normal limits.
Shiro's act of stacking Berserker Skills can be called suicidal if not for her tenacity and ridiculous vitality. And even then, she was near death the moment the skills wore off.
While healing the dragon, Shiro wondered how to forcefully make them enter a berserk state so that they continuously drain their life force away.
