Christ alive, this wasn't a merger, and as far as I know, it wasn't a bug exploit. Some very clever characters presented Malus with a set of facts that, when measured against what he already knew, pointed to an outcome that he found so abhorrent that he abandoned a realm named after himself. This was neither convenient nor easy for me as a player, but it is exactly what the character would have done.
Man, I approached things completely the wrong way.
This sort of thing does make me wish I was back in Luria though.