Harrow the ninth
(Book)

"Nothing is as it seems in the halls of the Emperor, and the fate of the galaxy rests on one woman's shoulders. Harrowhark Nonagesimus, last necromancer of the Ninth House, has been drafted by her Emperor to fight an unwinnable war. Side-by-side with a detested rival, Harrow must perfect her skills and become an angel of undeath -- but her health is failing, her sword makes her nauseous, and even her mind is threatening to betray her."--Publisher.