The Crest of Annihilation is a crest found in Nede with the power to infinitely increase spatial mass when granted enough energy, and thereby, summon an instant Big Crunch, which would destroy the universe.
Discovered by the Nedians in 4 billion years BC, the Crest of Annihilation has been kept in safety, and its use has been considered forbidden, as it would bring the destruction of the universe itself. The crest has the ability to actually use energy to create mass, thus changing the total mass of the universe. When given enough energy, the crest is somehow able to create a point in space with infinite mass with a gravitational force of infinite proportions. This can, theoretically, cause the expansion speed of the universe to become minus infinite, thus causing an instant Big Crunch.
Unfortunately, it was stolen by the Ten Wise Men in S.D. 366, on their return to Energy Nede. Along with the Quadratic Sphere they were sealed in, they prepared an antimatter cannon capable of even passing through Energy Nede's shield that covers it from the outside. With it, Gabriel planned to destroy the universe.
In the aftermath of the final confrontation in Phynal, Gabriel reveals that he had programmed the crest to trigger its effect upon the death of all of the Ten Wise Men. The Crest of Annihilation is finally activated and attempts to destroy the universe, but Rena Lanford was able to use the Crest of Enchantment before the universe is destroyed. Unfortunately, the shaking continues a short moment after the Crest of Enchantment is applied, but both Mayor Nall and Dr. Mirage reveal that the use of the Crest of Enchantment does not entirely cancel out the effects of the Crest of Annihilation, but instead divert its effect elsewhere, which they reveal is Energy Nede itself. This caused the Crest of Annihilation to only affect Energy Nede, with it's enveloping shield which was able to hold the crest's effect, preventing the Crest of Annihilation from destroying the universe. This marked the end of the Nedian civilization, making Rena (and/or Chisato and/or Noel if they are in your party) the sole Nedian(s) left in the universe.