Kiesarishi Mono

Est has long been under the protection of a guise of death. Aravis, a wizard and its lord protector, ventures out on a quest for answers and a higher power, against his sister Tule's wishes. Far from fulfilling it, he is banished—and returns only to find Est in ruins, Tule little more than dead, and himself sapped of power.

(Source: Lovely Strange Dark)