WarGreymon X

WarGreymon X is the supposed leader of the X-Digimon that fight the Royal Knights. He first appears when he tries to tell some non-X-Digimon that Yggdrasill is their enemy, but when Omegamon appears, he has to fight against him and is later forced to flee. It is during his escape that he asks Dorumon to watch Tokomon, since he is unable to both fight against Omegamon and take care of a child. He later escapes Omegamon and tells his friend MetalGarurumon X what happened, who can not believe that the Royal Knights are their enemy. Later WarGreymon X has another fight with Omegamon to protect Dorumon, during which MetalGarurumon X seemingly dies. He later fights against a large number of DexDoruGreymon, together with other Digimon and when the crowd of evil Digimon nearly deletes the Digital World he is among the Digimon which still existed. It is unknown what happened to him after the Digital World is recreated.

(Source: Digimon Wiki)