The graduation set in Dungeon Fighter Online referred to the best set of equipment collected in the game, which usually had the highest attribute bonuses and the highest combat power. In Dungeon Fighter Online, the graduation set was usually made up of six pieces, each with different attributes and effects.
The Dungeon Immortal Wargod's graduation set usually consisted of one weapon, one armor, and three accessories. Weapons usually had the highest attack power and damage bonus, while defensive equipment usually had the highest health and defense. Jewelry usually had the highest attribute bonus and additional skill effects.
The graduation set required the players to collect all kinds of equipment during the game and upgrade and strengthen them to increase their attributes and effects. Players with graduation sets usually had the highest combat power and the strongest gaming experience, so they were one of the most popular characters in Dungeon Fighter Online.
The fanfiction might play with the technological elements of the 13 Sentinels Aegis Rim universe. It could introduce new types of sentinels or upgrades to the existing ones. This can add an exciting new dimension to the story. Additionally, the relationships between the characters can be explored in a romantic or platonic way. Some fanfictions may focus on a particular pair of characters, developing their relationship in ways that were only hinted at in the original game.
One popular theme is time travel and its consequences. Since the game has elements of time - shifting, fanfictions often expand on this. They might explore what would happen if a character got stuck in a different time period or if they changed something in the past that had a huge impact on the future. Another common theme is the mystery behind the alien invasion. Fanwriters may try to come up with their own theories and explanations, adding more layers to the overall mystery.
It could be about the power and protection associated with the gods, given the mention of 'aegis' which is often related to divine protection in mythology.
I'm pretty sure Valor isn't based on a true story. Usually, if it were, there would be clear indications or it would be widely publicized as such. But in this case, it appears to be purely fictional.