Seraphimon is the most powerful Digimon alive, he has been alive for many years, he was orphaned, and trained under Baihumon. Unlike Opossumon, he passed the test, and Opossumon ran away. Patamon trained for years and Digivolved all the way to Seraphimon.
Baihumon was killed by Lilithmon, and Seraphimon swore that Baihumon will not be in vain. He later recruited a small army, and which included his apprentice Sorcerymon, sometime during this war he turns the 6 Great Warrior Digimon into the DigiMemories, he hid them, and Lilithmon got her hands on the 6th one, also during this time, he had the Zeo Diamond with him.
Later on Ian Parks was put under a spell and became the Silver Ranger, and totaled the link Seraphimon has. But he was brought back later. Seraphimon happily welcomed Ian to the team along with Gumdramon.
Seraphimon later sees 4 of his original Rangers off, Dan, Trini and Bradley left for New York for a Peace Conference. Sonia later leaves to pressure a gymnastics career. Seraphimon is sad to see his friends leave but he wishes them luck.
Seraphimon manages to return to the Digital World, with Kokuwamon, leaving the Digi-Rangers in tears. But Ophanimon and Datamon take over.
Patamon is Seraphimon's Rookie level, when he was training with Baihumon. He passed a test, being the youngest Digimon to do so.
Angemon is the Champion form of Patamon. Angemon is a six-winged angel dressed in white and blue clothing. Like many other humanoid-like Digimon, such as Angewomon and Kazemon, his eyes are covered by his helmet and are never seen, giving him the appearance of a blind prophet.
Angemon was seen while Seraphimon was training, under Baihumon.
When Seraphimon was in this form, was when Baihumon died, and Seraphimon started to fight back.