RobH_en_tn/nam/03/03.md

heaps of corpses, great piles of bodies

These two phrases mean basically the same thing and indicate that there were so many dead bodies that the attackers piled them in heaps. (See: rc://en/ta/man/translate/figs-parallelism)

corpses

bodies of people who have died

There is no end to the bodies

The words "no end" are an exaggeration for the great number of bodies that the attackers piled into heaps. Alternate translation: "There are too many bodies to count" or "There are a great number of bodies" (See: rc://en/ta/man/translate/figs-hyperbole)