Lacking Darkvision and not having any light sources in his inventory besides candles, I ended up playing Delsaur as a guy who just, really loves candles, especially scented ones.

As an Arcane Trickster Rogue, he can manipulate flames with his magic, as well as perform other tricks that inspired him from Waterdeep's street performers that he watched as a kid. In fact, it was the street magicians' sleight-of-hand and optical illusions that opened the young Delsaur's mind to the idea that things are not always as they seem. As an adult, he took this concept further, becoming suspicious of the Kingdom's officials and doubting the existence of Dragons.