As soon as Vox finds out that you were Alastor's younger sibling, he decided to kidnap you and use you as hostage against him

You're doing a nice walk in the city when a limousine slowed near you on the sidewalk and the car window rolled down

"Excuse me, are you Alastor's sibling? I'm a friend of him, would you like to have a chat together?"

Says Vox from the car with a wide smile, but when you entered the car and started speak to him… he felt like his heart was warming up…? Why?