Serena and Veronica were split a soul at birth because Serenica was a Sage.A Sage; a Prestige Class that combines combat magic and healing magic; with a few tweaks. However, no one is born a Sage. Therefore her combat magic went to one reincarnation; and her healing magic went to the other. The sliver of soul that was her Sage self stayed with the Keeper of Time.
- This is why it was possible for Veronica's soul to fuse with Serena's after her death; their exploits; especially in the face of Yggdrasil itself; counted as the Sage Ceremony.
- This doesn't mean they have half-souls; they grew into individual wholes like starfish.
The Old Timeline still exists.For the party; it looks as if the Luminary simply vanished.
- The same way Serenica vanished to go save the original Luminary in the post-game ending. The timeline the Party was in stayed the same.
Alternatively, the old timeline was destroyed when the Luminary shattered the Orb of Time, and the different depictions of how it happens is important.When the Luminary does it, it shatters the Orb to pieces and his Blade of Light is destroyed, which represents that timeline being torn apart to give place to the new one, however, when Serenica does it, it merely makes a dent on the Orb, and the Blade of Light remains whole, representing that there is a "flaw" in that timeline, that is, her absence as The Timekeeper, but otherwise the orb is still whole, this is caused by different intents behind the strike, when the Luminary did it, he did not only intent prevent Veronica's death, but also to prevent all the suffering and deaths that Mordegon caused, while Serenica knew that to destroy a timeline that had achieved true peace on its own would be wrong, and she was simply seeking personal resolution. This would explain why multiple characters besides the Luminary display subconscious memories of the original timeline.
Alternatively, Serenica traveled to the future to meet the incarnation of Erdwin.This explains why the orb and the sword didn't break. As well as tying Serenica to be the mother of the Dragon Quest III protagonist.
The Luminary having Shypox is canon.It explains his Heroic Mime status, and seeing as it's a disease that one can catch later in life, it doesn't interfere with him being talkative as a six year-old.
The dog Sandy is a Legacy Character.Sandy is shown as a puppy when the Luminary travels to the past and sees himself at the age of six, as explicitly stated by Amber, which should make Sandy over ten years old at the beginning of the game. That is very elderly for a large dog, yet Sandy does not act like it at all. Furthermore, having puppies at that age would be extremely dangerous, if it's even possible. It's much more likely that the Sandy seen in the past is the mother or grandmother of the current Sandy, and in each generation of puppies one is named after her mother.