Project Arc

Project Arc (プロジェクト・アーク) is a plan set up by King Drasil where it would use the X-Program to delete 98% of all Digimon.

Digital Monster X-Evolution
The Project Arc was the main plan of King Drasil, where he put the remaining 2% of the selected Digimon to live in the new Digital World.

Digimon Chronicle X
After kills, King Drasil removes the barrier between the old and new Digital Worlds and Kota Domoto and Yuji Musya promise King Drasil they will try to find a way to expand the capacity of the Digital World so that King Drasil doesn't have to use Project Arc.