Wait wait wait wait, I literally cannot believe I’m asking this question for the first time in my life, but I was listening to the SR2 dialogue before bed, as you do, and it just fucking hit me -
If the Pillar Guardians relinquish their role as guardian at the moment of their death, as we saw happen when Ariel was murdered and Kain immediately inherited the role as a baby, then why did Kain retain guardianship when he was murdered? Like you could say that Ariel was left to natural forces when she died while Mortanius had basically god-like powers over Death with which he pulled Kain back from death and he might have restored Kain to guardianship at that same time, but Mortanius wasn’t the one who killed him or even present when Kain was killed. Kain literally woke up in a crypt when he was resurrected and has memories of an afterlife, so more than sufficient time had elapsed between his death and reanimation for a new Balance guardian to be born.
( Oh boy... )I FUCKING HATE THIS SERIES.

