In this game you will only gain 50% normal kill xp. Instead you will gain more xp through other means in this game, by doing domain/character actions, by providing articals to the Bards/News, by staying active on the forums, by archiving great things for your realms, partaking in battles and so on.
In addition its important to note for kill xp that you'll effectivly be counted as higher level for the sake of XP gain. Affectivly the scion receives a level adjustment depending on his bloodline strength: +0 ECL (Minor), +1 ECL (Major), +2 ECL (Great), or +3 ECL (True).