Okay, so like, here’s the facts. Lucretia had to figure out new lives for Magnus, Taako, and Merle with only the ability to take away information via the Voidfish.
As we know, Taako just got hooked up with his show, feesibly without any further erasing needed. I headcanon that the original Merle from Faerun died as a baby, so Lucretia only had to erase the fact that he died to place her Merle with this plane’s version of his family.
But Magnus insists that he was born and raised in Raven’s Roost. And as far as we know, no one ever questioned him on it. So how can Lucretia give him a lifetime at Raven’s Roost if she can only erase something?
The answer: she erased the fact that he’s a stranger. Maybe she wrote down “Magnus Burnsides is not from around here” onto a piece of paper and threw it into the tank without really thinking it through. Because now it’s not just the people of Raven’s Roost who is pretty sure Magnus Burnsides has been here his entire life even though evidence suggests otherwise. everyone in Faerun has this vague sense that Magnus Burnsides has been a vaguely familiar face in these parts for a long time, even if they can’t quite place why.
Magnus tells a barkeeper in Bradybuck that this is his first time here and the barkeeper doesn’t say anything, but they’re pretty sure Magnus has been stopping through here their entire life. Maybe they’re wrong, but either way his familiarity makes him easy to talk to, if not downright comforting to be around.
What I’m trying to get at is that one of the stranger side effects of the voidfish’s static is Magnus’s rustic hospitality.