"Malthael's fallen angels have brought death to Westmarch, raising an army of reapers from the city's slain defenders. Once, those men and women were our protectors. Now, they are our executioners: scouring the city for every living soul and putting them to the sword."— Lorath Nahr(src)
Summoned Soldiers are faster than Summoned Shield Guards, and their blows deal Cold damage as well.
They cannot be summoned by Death Maidens, but often spawn for events or just accompany other Reapers in the field.