Sister Lamia

Sister Lamia is an NPC who greets Luka on his way to the city of Grand Noah. She is first in disguise as a human, but then reveals herself to be a Lamia after Alice calls her out on having a bad disguise. She is a devout follower of Ilias's teachings, even though she is one of the monsters Ilias hates.

Trivia:
Judging from recent screenshots, Sister Lamia appears to be an enemy in the upcoming Part 3.