When I was playing I understood it as "he will be a regular vampire lord with vampire lord powers, but he will feel nice physical aspects of mortal existence and will be able to live under the sun".
Again - if you fulfill the pact with archdevil, it's impossible the consequences will be good.
EDIT: As for the family, at first I also thought Astarion doesn't really treat the other spawns as a family. That's why I was surprised when he said with trembling voice he feels sorry for them. I guess that's what happens if you share 200 years of torment with other people.
Last edited by Phea; 05/09/23 01:58 PM.