Veil of the Once-Queen

From the introduction: Deep in the forest stands Tanibel, a remnant of the long-dead Martoi empire: a tall citadel surrounded by a mockery of a living town. Using their magic to straddle the veil between the worlds of the living and the dead, they survive in a dream of their vanished reign. From the side of death they draw their patience and eternal nature, from the side of life, their vigor.