BlackWarGreymon is very similar to WarGreymon in stature and size but the differences are BlackWarGreymon doesn't have the crest of courage on the back of his Black Chrome Digizoid Armor.
Intent on destroying the DigiDestined once and for all, Arukenimon created BlackWarGreymon from 100 Control Spires to perform the task. He managed to easily defeat Paildramon and the DigiDestined's other digimon without even trying. But when given the order to finish the job, BlackWarGreymon refused to obey Arukenimon and simply flew away, stating that he wasn't going to take orders from someone that was weaker than himself. It would turn out that, due to the number of Spires used in his creation, BlackWarGreymon had developed a conscious mind and self awareness, separating him from his 'mindless' siblings, but it also made BlackWarGreymon confused about his purpose in life, with many questions that needed answers.
On his quest to find his true destiny, he fought against a herd of artificial Mammothmon, posing them questions they were unable to answer simply because they were mindless and followed Arukenimon's orders without question. During his fight, he notices a tiny flower about to be trampled by a Mammothmon, and protects it by destroying the herd. Afterward, he begins to question his actions, and even why the flower was considered a living being, but he was not; in the end, he crushes the flower under his foot. Afterwards, he would encounter Agumon, who tried to help him answer his questions. While Agumon wasn't successful in answering any of them, BlackWarGreymon was being brought round to Agumon's way of thinking. However, just as they were about to shake hands to mark a friendship between the two, BlackWarGreymon began suffering from intense pain, and left to find the source, which was a Destiny stone being damaged by an artificial Knightmon with the DigiDestined working to stop him. BlackWarGreymon easily defeated Knightmon and destroyed the Destiny Stone in the process. BlackWarGreymon then worked to destroy all the stones and saw Azulongmon when he destroyed his third stone. BlackWarGreymon deemed Azulongmon as his "worthy opponent" and made it his mission to destroy all the Destiny Stones in order to find and face Azulongmon, convinced this was his purpose in life. BlackWarGreymon continued working to destroy the Stones with the DigiDestined attempting many times to stop him, but he always got the better of them. Even when the last stone was protected by the combined might of Paildramon, Silphymon and Shakkoumon, BlackWarGreymon managed to take them all on despite the injuries he took, many of which resulted in him spurting oil from his cracked armor. Just as the DigiDestined attempted to move the Destiny Stone out of harm's way using their D-3's, they inadvertantly activated the Destiny stone, summoning Azulongmon. BlackWarGreymon attempted to fight Azulongmon, but Azulongmon refused to fight and explained to BlackWarGreymon the Control Spires he was created from were a contributing factor to Azulongmon being sealed away. He also explained that all things had a purpose in life, but BlackWarGreymon could not get the questions from anyone else, he had to find the answers on his own. Thankful for hearing that and his rage subsided, BlackWarGreymon left to find his true purpose.
On December 27, BlackWarGreymon emerged in the Real World to find/kill Yukio Oikawa for disrupting the balance of both the Real World and the Digital World as he deemed since he created Mummymon and Arukenimon with his own DNA, Oikawa did not belong in either world after realizing his lack of answers for the questions of his existence in the Digital World, which caused Oikawa to see BlackWarGreymon as ungrateful. However, before he could kill the man, WarGreymon intervened and engaged him in battle. The raging battle spread into the nearby city, neither side able to gain the upper hand until the fight was joined by Imperialdramon Fighter Mode, who together with WarGreymon finally defeated BlackWarGreymon. After the battle it took lectures from Wormmon, Agumon and Veemon about the importance of life to convince BlackWarGreymon to enjoy life's pleasures and talk him out of killing Oikawa.
BlackWarGreymon showed up when Cody Hida's grandfather tried to talk Oikawa out of his plan. Myotismon momentarily took over Oikawa's body and with the additional power from absorbing one of the Dark Flowers, fired a blast of dark energy at Cody's grandfather. BlackWarGreymon stepped in front and took the full blast, saving Cody's grandfather's life, but he was mortally wounded by the blast. Oikawa fled and BlackWarGreymon realized that Myotismon was actually controlling Oikawa like a puppet. He used the last of his strength to seal the Highton View Terrace Gate to the Digital World to prevent Myotismon from entering the Digital World at that point. In the process, he found the purpose he had searched for all along and died a hero's death. An image of him is illuminated on the tiles being formed by the first DigiDestined's Digimon in the Digital World.
When Oikawa attempted to open the gate, they were thrown into an odd dimension, where Myotismon found himself overpowered by the DigiDestined. In the last episode, all of the original DigiDestined had to trek all the way to their summer camp location as that was the closest gate to the Digital World.
BlackWarGreymon is a reoccurring boss in chapters of Digimon Tamers: Digimon Medley. Each time, he will defeat the DigiDestined's Digimon in several turns, but the damage he sustains will carry over from battle to battle.
- Terra Destroyer (Gaia Force): Similar to WarGreymon's Terra Force, he creates a massive sphere of energy and throws it.
- Dramon Destroyer (Dramon Killer): A thrust with his claws.
- Black Tornado: He begins to spin and becomes a tornado, then rushes into his enemy.
The name "BlackWarGreymon" refers only to the Mega form of this Digimon.