WARNING: The following contains spoilers for Episode 8 of The Strongest Sage With The Weakest Crest, "The Strongest Sage Goes on a Journey," now streaming on Crunchyroll.
Matthias "Matty" Hildesheimer is the reincarnation of Gaius, a powerful sorcerer who was originally a member of an ancient race of humans. In his previous incarnation, Gaius was a master of spellcasting and built powerful tools to aid him in combat. As such, he formed a strong reputation as a dangerous enemy of demons, which continues to follow him 5,000 years after his death. Ironically, many of the modern demons Matty fights haven't caught on to his real identity yet, which he uses to his advantage and goes as far as to request his oldest friend Iris to remain tight-lipped about his secret.
In his current incarnation, Matty has been traveling along the Dragon Vein, which is also being used by demons to silently invade human kingdoms and other communities. In the first kingdom he stationed himself at, Matty enrolled at the Second Academy and taught the students there silent spellcasting. This allowed the students to develop the skills needed to defend their kingdom against demons, but it also bought Matty enough time to create a powerful magic barrier to repel them. With his task completed, Matty departed the school to continue his travels, which brought him to the town of Melkia.
Upon arriving in Melkia, it doesn't take Matty and his companions Lurie, Alma and Iris long to realize there is something terribly wrong with this town. The first sign of trouble manifested in the form of magical lampposts being banned in favor of more dangerous high-tech ones. The second sign of trouble they identified was the mysterious death of the town's previous governor and being subsequently replaced with a lord of a more questionable character. The third sign that Matty and his friends couldn't ignore was the new lord driving out the town's healers and sending its adventurers down to their deaths in the town's dungeon.
With too many dangers lurking about, Matty and his friends decide to stay in the town to take down the new lord, who Matty suspects is in league with demons. Episode 8, however, reveals that the new lord is far from the town's greatest threat. While Matty succeeds in getting his king's approval to arrest him with his proxy, Eik, the more dangerous threat to the town's safety is lurking in the dungeon below. Deciding to investigate further, Matty and his friends descend into the dungeon's depths, only to discover the Dragon Vein is being manipulated by a demonic spell, which is also luring outside monsters to the town.
Matty asks Lurie to restore the Dragon Vein, with Alma and Iris being tasked to hold off the monsters. Matty himself goes down to the part of the dungeon where a demon is waiting to fight him specifically. This is the first time demons find Matty threatening enough to develop a battle strategy against him. However, the bigger surprise for Matty is that the demon waiting to fight him is itself being instructed by an ancient demon who knows Gaius and suspects that Matty is his reincarnation. For once, an enemy risks exposing his secret, which actually excites Matty.
During his battle with the demon, Matty eavesdrops on the telepathic conversation between him and the ancient demon to learn more about his new enemy. In their telepathic conversation, the ancient demon reveals his uncertainly that Matty could be Gaius based on the fact that he hasn't defeated the demon yet. The Gaius he knows would've killed him without hesitation, although it doesn't occur to him that Matty may not be fighting at full strength and could be stalling as a way of gathering information. Once Matty learns everything he can from the telepathic conversation, he promptly kills the demon and converses with the ancient demon himself.
In their own telepathic conversation, the ancient demon challenges Matty to locate him, to which he acquiesces. Matty, however, realizes the ancient demon is masking his actual location. This impresses the demon, who then challenges him to locate him if he wants to engage him in a fight. Matty accepts the challenge, although whether it's a decision he'll come to regret, only time will tell. Based on what's known about the ancient demon thus far, he could've already fought Gaius hundreds of years ago. Either that or he could turn out to be someone from Gaius' past -- like his friend Reuter -- who allied himself with demons.
