Complex sentence: Unfortunately, despite Burns' death, Bart still remains a vampire, and to make things worse, Lisa discovers that everyone in the Simpson family except herself is a vampire, and that the true head vampire is inexplicably Marge, not Burns.
Split into simpler sentences: Unfortunately, despite Burns' death, Bart still remains a vampire. To make things worse, Lisa discovers that everyone in the Simpson family except herself is a vampire, and that the true head vampire is inexplicably Marge, not Burns.