Xros Code

The Xros Code (クロスコード) is an abstract concept consisting in an inherent energy which only possesses a few little portion of humans. This energy generates the potencial to allow them to pursue their dreams no matter how difficult they are and make feasible to manage a Fusion Loader and to perform the DigiFuse. Therefore, all the protagonist Generals carry it to a greater or lesser extent.

Digimon Xros Wars (manga)
It is introduced for the first time in the Chapter 9 of the manga by Nene Amano under the orders of, who knew the real power of the DigiFuse thanks to his elder brother. This is the reason why Christopher, Nene and her little sister Kotone were attracted to the Digital World. Originally, AxeKnightmon said that it was a double-edged weapon because it could exhaust the vital energy of its carrier. However, later it is revealed that he lied in order to manipulate Nene. The aim of AxeKnightmon is to obtain the Xros Code of Mikey or Christopher (only one of them because they are too pure to be combined) and, with the help of Kotone's and Nene's ones, configurate the Darkness Loader and thus increase its potential through the Forced DigiFuse. In the manga, the strongest Xros Code belongs to Kotone, closely followed by Taiki's one.