Complex sentence: The Worlogog was an ancient artifact constructed (possibly by Metron) from solid tachyons, containing a map of the universe in miniature which a mortal (or immortal) mind can alter mentally, causing reality to shift to fit the new map.
Split into simpler sentences: The Worlogog was an ancient artefact constructed (possibly by Metron) from solid tachyons. It is a map of the universe in miniature which a mortal (or immortal) mind can alter mentally, causing reality to shift to fit the new map.