Danny and Jon/Aegon did the Dothraki dirty. Just ride into a black void and get slaughtered. Even Melissandra's assist didn't do anything.
That was so contrived. A real battle would have had the Dothraki do hit and fade flank attacks in the *daylight*. I suspect Melissandra's bit was to add to the drama so the defenders could watch the lights go out from the castle walls.