I mean, in a way it's common on Earth too. There's two sets on DNA in every cell, some creature that's symbiotic with pretty much every other creature to the point that it's just part of the cell. I looked in some biology books and I think it's called mitochondria? But that doesn't really seem the same, they can't separate at all.

It is! Hopefully my world can deal with me disappearing, at least in a 'reality doesn't start throwing out person-not-found-errors' kind of way, but other than that I'm not concerned.