Guardian

Guardian is a traditional honorific used when someone of Eisan origination encounters an Arcana, especially while visiting Terra.

History

During the Council of 1090, the magical creatures of Terra first met to discuss the possibility of splitting off, as the mood of the Church was making it increasingly more difficult to continue living in peace. Soon after the negotiations began, there developed two factions that, while they didn't disagree about the problem, saw two different solutions to the problem. Those who decided to remain took on the name of Arcana as a collective noun to describe themselves as a separate group within the larger population of Terrans who presented a threat to magic's continued existance. They argued that even if their people split off, there would always be more magical people and beings born in Terra. As such, it was unlikely the Church would stop targeting them.
A group better able to blend with the larger population would be less likely to draw attention from the Church, and more likely to find their people before they attracted untoward attention. Those who made the suggestion were not willing to suggest something they would not take on themselves, so volunteered  do this for their community. They understood that in doing so, they would have to go underground for their own protection, and are largely seen as the Guardians of the magical world and beings who continue to live on Terra.
During the next wave of attacks that occurred during the 1100s, they helped to move people ahead of the inquisitors who sought them out for the Witch Trials that moved through the world in waves. For every wave of iradicating those who show talents for things they shouldn't, and were unable to conform their magic to the acceptable shapes the Church allowed, there were Arcana opening portals and nudging people through.
Over time, even early acceptance of their magic by Church officials could turn if there was a decision by new leaders that viewed it counter to how their predecessors did.
Some of those Arcana gave up their lives in the process of saving as many of their own as possible, and while they don't have the names saved in the history the way those among the Arcana do, Eisans have long memories.
Even though the Church is largely believed to no longer be interested in persuing the magical the way they once did, Eisans still remember the number of times the Terran Arcana helped save their own. Therefore, when they encounter each other during an interaction, Eisans regularly use the honorific with sincerity.