Retrocausality: Could Spike and Drusilla's being able to love and feel jealousy have something to do with Angel's gaining a soul, even though that happened decades after both were sired? In the Angel episode "Why We Fight" it turns-out that his sole scion was 'tainted' by Angel's soul, and Magic may not care as much about causality as we tend to do…. Con: none of Spike's scions in Season Seven seem nice at all, but <handwaving about the The First Evil's being in the driver's seat when he made them>.
Retrocausality: Could Spike and Drusilla's being able to love and feel jealousy have something to do with Angel's gaining a soul, even though that happened decades after both were sired? In the Angel episode "Why We Fight" it turns-out that his sole scion was 'tainted' by Angel's soul, and Magic may not care as much about causality as we tend to do…. Con: none of Spike's scions in Season Seven seem nice at all, but <handwaving about the The First Evil's being in the driver's seat when he made them>.