The Gluttony Labyrinth is the second Dusk Circle that has materialized. Although it has been active from the beginning of the story - God's Gift and his heroines can only visit it after beating the Lust Labyrinth.
It is unknown when it activated exaclty, but it was definitly prior to the story line.
After beating the Lust Labyrinth, God's Gift and his selected heronie enter the labyrinth alongside their Star Children.
On the forth floor God's Gift discovers a huge amount of so called Dark Crystals - which attract monsters. Via the Vis-O-Matic Ruby Coiler askes him to get some of these Crystals for the Lab. Although Mark Flask was against it, Ruby still insists on God's Gift bringing her at least one.
God's Gift accepts it and takes one with him.