Matters of the heart are unpredictable and most of the times hurtful. Love is such a one word but means a lot to someone who's down to earth and ready to do anything for it, some travel unspeakable distance just to find it. To feel it as it's the only thing that makes them alive even just for a little while.
It was love that had Antonio come back early at home just to see Nina. His flower and a place of comfort which brought him peace and sanity, he abandoned his brother's mission for the sake of love. He wanted to spend Christmas with Nina as they hadn't spent any holiday for nearly nine centuries after all things went south.