Night of Wallachia

Night of Wallachia is the 13th of The 27 Dead Apostle Ancestors. He doesn't actually exist, and his nature is that of a phenomenon known as TATARI, a recurring event that grants physical shape to the fears and rumors that circulate within a community.

Spoiler

His name before becoming TATARI was Zepia Eltnam Oberon. He was a genius alchemist from Atlas and the ancestor of Sion Eltnam Atlasia.