World Break: Aria of Curse for a Holy Swordsman

World Break: Aria of Curse for a Holy Swordsman (also known as Seiken Tsukai no World Break) is a 2015 action-fantasy harem anime.

It follows Moroha Haimura, a new student at Akane Academy, a special school where "Saviors" (reincarnated heroes with memories of their past lives) train to fight monstrous beings called Metaphysicals that attack humanity.

Saviors are divided into two types: Shirogane (who manifest weapons and physical techniques using prana) and Kuroma (who wield destructive magic using mana).

What makes Moroha unique is that he's the first Savior to awaken memories from two past lives: one as Flaga, a heroic swordmaster prince, and another as Shu Saura, a powerful dark magician/king. This lets him use abilities from both classes.

He quickly gets tangled up with two girls tied to those past lives:

• The energetic and competitive Satsuki Ranjou, who was his little sister (Sarasha) in his prince life.
• The cool and composed Shizuno Urushibara, who was his wife in his dark lord life.

The story mixes battles against Metaphysicals, school life, and a classic harem setup as the girls (and others) compete for Moroha's attention, while he leverages his rare dual powers to protect everyone.

It's a fairly standard supernatural school action-romance with ecchi elements, based on the light novel series.