Simplify the following text for a Grade 7 native English-speaking person.
Original: Angel was a spin-off of Buffy the Vampire Slayer , featuring Buffy 's vampire-with-a-soul ex-boyfriend as the title character .
Simplified: Angel was a spin-off of Buffy the Vampire Slayer . The series was named after Buffy 's vampire-with-a-soul boyfriend .