Blood

Klaus wiped the blade and also his brother's lips, and patted his head affectionately as if he had been a good boy for taking everything. It exasperated Alexa.

Only then, the First Prince answered her question,

"What am I? I don't know."

The Princess watched the effects of the 'medicine' on her husband's body. Alexander's cheeks seemed to become pinker and it agitated his breathing for a moment. As well as his heartbeat, gradually returning to normal.

"This is incredible…!"

"Incredible? I don't know," Klaus chuckled bitterly, sinking his head back into the pillow and looking at the canopy ceiling. "But if it helps saving my brother, then it can't be totally bad. Maybe I just have to be what I am and pay the price for it."