Each chapter contains some extra artwork for it. One for the start, one for the end.
They have a random chance to appear on the title screen after completing the chapter.
This chapter gives the player one of the many Remnants, items that buff characters but also provide an additional story.
Another music track, this one being a clean version of the Mourning Mother fight. The audio during the battle is compressed, so this provides a clearer version.
[ Lost Archives IV ]