Soul Sacrifice and SS Delta

He leaves Sanctuarium with the world on its knees, Sanctuarium's own members losing faith. Just when it looks like Sympatha is genuinely losing faith herself, about to be set upon by her last few followers, Aegrus returns, defeating and sacrificing all those who had become monsters. Why? Because he truly believed in everything Sympatha and Sanctuarium stand for and was willing to sully his own body (by sacrificing monsters again, despite having sworn never to do so again) to avoid her having to do the same.

I assume you're referring to the shared name of trapped prisoner in the cage (the one reading Librom) and the final surviving member of Sanctuarium once Aegrus is done with them? My initial assumption was that the player character is their son, but that's based solely on the surname found on the spine of the book in his cage; he could simply be a brother or another relation of the same bloodline.

Pretty much he is likely the brother or son (aka the fourth Lenixion).  Its pretty cool when you think about it.  I'm also curious if we're suppose to assume that the memory issues that Magusar has is because he absorbs Persapius, which is likely to happen in any continuity considering that happens preillusion.  There's  lot of other tidbits if you think about it to.  For example SS Delta is in actuality a sequel.  The sorceror you play in SS sacrifices Magusar and is the magusar from SS Delta.

I figured that Delta is a recursion of Vanilla SS, and that pre-revision you essentially are Delta's Magusar, hence why the name on the spine of the book disappears if you select pre-revision.  Magusar's memory problems aren't that at all - it's just that thanks to the recursion, he's one body containing likely tens if not hundreds of thousands of souls - Persapius and all previous Magusars included - and his glimpses of the future are simply old memories of the recursion.  

The main story mechanic isn't exactly new, Mass Effect did something similar, as did The Matrix, but it was done in a way that remained interesting throughout, even if I was genuinely gutted when Sortiara showed up again, only to fade away, and Similia gives her life for you, her only real friend.

I assumed Vanilla SS was what the typical recursion was, basically the endless cycle.  Delta was the exception to the rule.  I mean if you consider that then persapius was always absorbed by Magusar, he always had to be considering no one else would've been close enough to challenge magusar.  The only reason I say that is because when the world is reborn that is the point that magusar loses everything and is basically reset.  So he has memories from that point onwards.  I mean he forgets everything pre-recursion, but also the magusar after the worlds rebirth is going to be a much weaker mage as well he likely was reset from the persapius situation.  Perwsapius also mentions he can gain new memories at a price of losing spells.

Lol ok that could be a lot more waffly then i wanted it to be and i'm not sure if it makes sense.