The protagonist of the original work is exactly one of the Masters from Chaldea.
The so-called Master refers to magicians who have forged contracts with their Servants and are capable of commanding them.
The way Chaldea intervenes in human history to protect the foundation of humanity mainly relies on these Masters and their Servants.
"When a threat that could affect the entirety of human history emerges, Masters from Chaldea, along with their summoned Servants, will appear to investigate, survey, and hinder the occurrence of such a threat, and if necessary, use extraordinary measures to proactively excise distorted threads of history and repair anomalies that have manifested in human history,"
Reiger explained to Altoria.
"This is Chaldea, and they are also the foreign travelers mentioned in the prophecy of the Mirror Clan,"
Upon hearing this, Altoria's eyes widened slightly.
"So the magicians from a foreign land referred to here are the ones sent by Chaldea?"
