Hayato, the one who was left behind.The first three are Digimon Adventure based, but do not intertwine in the same universe. Yohji's more of a Tamer's side story, like an hour-long movie. All four also make an appearance in DSDC, as a group of military agents with Digimon that had no hold on /any/ of the stories. And it's /that/ group that's called the Digimon Soldiers.
Jasir, never human and lost to concept.
Ryoushi, the lone and faithless hunter.
Yohji, the shadow in Rika's mirror.
Faith Renewed /// Jogress Traitors
(Story of Ryoushi)
His Bleeding Sorrow
(Story of Hayato)
The Devious Tamer
(Story of Yohji)
Unearthly Encounters of the Digi-Kind
(Story of Jasir)