In the Persona Club P4 developer interview, Katsura Hashino defines the Myriad Truths as being the representation of how in a world full of misinformation, you can only truly believe in the words of those close to you.[1]
Nomenclature
Names in Other Languages
Language
Name
Meaning
Japanese
幾万の真言Ikuman no shingon
Tens of thousands of truths / mantras
References
↑ Translation: "Yes, definitely. The ability Izanami uses in the battle, "Thousand Curses", I imagined it as a metaphor for all the lies the media tells. And likewise the ability the player uses, "Myriad Truths", that represents the trustworthy words of those people closest to you. I hope players get the message I was trying to convey, that no matter how much irresponsible, unverifiable information the world tries to deluge you with, you can always rely on the truths of your trusted friends to see you through." "Chapter: Developer Interview", Persona Club P4, Atlus, Famitsu Editorial Staff. Published by Famitsu (2009). Japanese. p. 395. Translation by Alex Highsmith. ISBN-13: 475774630X.