Michael alters his voicebox so that his voice sounds like souls, howling in pain...
"Whhhhhhhhy did you killllllll meeee? You havvvve sssssssenttt meeee toooo hellllll! Nowwww THEYYYY havvvvve sssssenttttt meeee forrrrrr youuuuu!"
With that, Michael changes his voice again, dropping the timbre and introducing sub-sonics to instill fear. He also begins to change his body to the demonic form described before.
"Mortal, you have been ours for some time. Now it is time for you to enjoy the rewards of your actions... in my domain.... I'm afraid that, of course, you must die first....."
With that, Michael slowly reaches foot long talons for Cartwright.
<assuming Cartwright panics at this stage and begs for mercy or some such, Michael will pause, as if considering>.
"You wish mercy? What could you offer me that would be more delicious than your dark soul?"
<should Carwright offer his loyalty and service, Michael will consider, whilst scraping talons across Carright's cheek and chest. After a minute, Michael will accept his offer, on condition that he tastes of Michael's blood>....