Digisoul

Digisoul (デジソウル Dejisouru)(Dub: Digimon Natural Ability, initialed to D.N.A) is a phenomenon by which an aura of energy, manifested within a person can invoke digimon evolution.

=Types of DigiSoul= Dark Digisoul: In Digimon Next, this was used by Kahara Shou and Inui Yuu. A Dark Digisoul uses the power of the Dark Area to empower a Digisoul, allowing Digivolution. However, it has serious effects on the user, Inui Yuu being knocked unconcious and requiring medical aid after his use of the Dark Digisoul. Strangely, Kahara Shou seemed to suffer no ill effects from his use of the Dark Digisoul, although this may be becuase he was in a far better state of health than Yuu and had darker emotions to begin with. It was used by Shou to Digivolve his Peckmon into Yatagaramon to fight AtlurKabuterimon and GeoGreymon, and by Yuu in his fury at Trailmon's death to Digivolve Gaomon into a black Gaogamon.
 * Artifical Digisoul (Jinzou Dejisouru): This is a sythethic form of Digisoul created by Kurata which was used to evolve Gizmon: AT to Gizmon: XT via the process of psuedo-evolution.