Spiritus Ater, part 1 is a manual in The Blood of Dawnwalker.
Look around, and ye shall see that breath is the fuel which brings the world forth. Humans and animals must draw air, or else they perish. Plants and fungi breathe too – listen closely, and ye shall know this to be true. The Earth itself inhales and exhales, sending forth winds and gales. In and out, light and darkness, so it has been, is, and shall be forever – not just in our realm, but on all other planes, too.
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Transcribed from DawnwalkerDB.