Revenge

T o  s o a r  w i t h  t a i n te d  w i n g s  i s  a  p r i c e  t o  p a y....

         ...f o r  s a v i n g  t h e  t h i n g s  t h a t  a r e  c o n s i d e r e d  p u r e...

 Research for Choas and Omega was conducted by Grimoire Valentine and Lucrecia Cresent.  They created the Omega Reports to provide further insight on the beings known as Omega and Choas as well as the Cetra Tablet for their project.

Soul wrought of terra corrupt,

Queling impurity,

Purging the stream

To beckon forth an ultimate fate.

Behold mighty Chaos,

Omega's squire to the lofty heavens.

Chaos is the antithesis of Omega and the "harvester of souls".  Chaos was known as another WEAPON to be used to help Omega's purpose when Omega was activated.  Chaos' job, in a sense, was to kill everything so that way Omega could absorb the Lifestream brought forth by Choas' destruction.  But because of the demonic strength of Chaos the Protomateria was created to be imbedded in Vincent's chest to control Chaos.  But in Deepground's plot the protomateria was needed, so the reason for tracking down Vincent becomes apparent.

So by killing tons of people and by swiping the protomateria from Vincent's chest Deepground managed to trick the planet into summoning Omega.  But by an explosive attack by Chaos himself, Vincent is able to stop Omega from asending and thus causes Chaos and Omega return to the planet.*

* All this information was taken from another Vincent Shrine.  Please credit them for this information.