As a vampire Luciel is blessed with great physical strength. However, to his knowledge he is also the last vampire still alive and always in danger of being murdered. With the final victory over the crown, the skeletons made it their goal to completely eliminate their strongest enemies. Alone, he has no choice but to hide and not be discovered in order to survive.
The loss of his people is reflected in his initial distrust and almost hatred of Arin. With his snooty and egocentric nature, Luciel is generally a rather complicated contemporary. Only for Ilias he would walk through fire since they have found mutual support in each other.