Operation Doodlebug (オペレーション・ドゥードゥルバグ Operēshon Dūdurubagu) was a plan devised by the Wild Bunch to revert the D-Reaper to its original harmless state.
The initial stages involved loading a version of the Shaggai program into Terriermon's ears, when in the form of Saint Galgomon would provide the centripetal force needed to produce a reversal spin within the wormhole between the Real World and the Digital World created by the D-Reaper. Yamaki then activated the Shaggai program, causing the direction the transphotic eddy to be reversed. When the angular velocity exceeded the speed of light, a backward flow of time was created, with the “Big Bang” effect produced by Shaggai having deminished the D-Reaper Zone it gradually began to dissipate through the vortex. The reverse flow of time devolved the D-Reaper back into it’s original, harmless state but coming at a cost. The Tamers' digimon began to devolve themseleves like the D-Reaper and had to return to the Digital World to prevent from completely disappearing from the plane of the Real World.
In order to successfully rescue Katou Juri from deep within the D-Reaper as well as to prevent sustaining damage or the risk of deletion inside the D-Reaper Zone, Shibumi wrote an algorithm, similar to the Blue Card, made to alter the wavelengths of the digimon’s digital make-up to match that of the D-Reaper.