[Story Spoiler]
About Flins:
Flins is a long-lived species,not a human.
There is a fragment of "Rächer of Solnari" Rerir in Flins’ lamp,which is also the source of the ancient power concealed within his lamp.
About Rerir:
He is currently in a fragmented state.
Albedo, Traveler, and others will defeat him later.