One thing that was on my mind all through Doctor Faustus was how Meph and Faustus act like they’re in love. From the oath:
“I, John Faustus of Wittenberg, Doctor, by these presents do give both body and soul to Lucifer, Price of the East, and his minister Mephastophilis…”
(Act II, Scene i, lines 105-107)
(Minor point: how can you give your body and soul to two different entities?)