* HeyItsThatVoice: Creator/CrispinFreeman is Albedo and Nigredo/Gaignun, with several instances of TalkingToHimself.
** Creator/JenniferHale is a young Nigredo/Gaignun in Episode II.
** Creator/DaveWittenberg is Allen Ridgeley.
** Creator/RichardEpcar is Ziggy.
** Creator/BrianneSiddall is Rubedo/Junior.
** Creator/LexLang is Lieutenant Virgil.
** Creator/KeithSzarabajka is Dmitri Yuriev.
* WhatCouldHaveBeen: The story was originally going to be very different for Xenosaga II and III before ExecutiveMeddling caused the scenario writer Soraya Saga to be dismissed and the original script by Takahashi to be discarded. A portion of the old script was retained for the Pied Piper cellphone game. Among some of the things that were originally planned to happen for Episode II:
** Citrine would reunite with her URTV siblings.
** Shion's past history with Febronia.
** Junior rapidly growing to an adult with both options available during battle.
** The ghost of old Miltia.
** The death of Sakura.
** Brief reunion between the URTVS and grown-up Citrine.
** Gaignun vs the Zohar emulators.
** Junior and Albedo vs U-DO vs KOS-MOS 3rd armament.
** Shion's spiritual seeking/witnessing/awakening.
** The truth about KOS-MOS (removed)
** Conversation between chaos and the Red Testament.
** Conversation between Nephilim and Abel.
** An antimatter annihilation of Albedo.