Captain Mistra

Love, is a burning thing - 

Mistra is a pirate captian who messed with a cursed demon necklace that summoned a fear demon (Leviathan) that tried to possess her. It made her run her boat into a cave, which was really an entrance into the demon world, but in the panic of the crew the boat caught fire and it burned Mistra's face. The commotion caught the attention of some mermaids who ate the rest of the crew, but Dawn took a liking to Mistra and saved her from drowning. Dawn's fae presence interfered with the demon magic of the Leviathan so he cannot fully possess Mistra, she's kind of half-possessed. She doesn't really know what to do anymore now that her crew and boat are gone so she spends some time on a deserted island, taking it slow with Dawn.