Era 2, the fourth moon, and a Death Rattle

[Brgst13]

I had an epiphany today going through the Death Rattles.  Many have a very clear interpretation, and these are pretty obvious in hindsight.  But there is one that still does not quite fit: "Three of sixteen ruled, but now the Broken One reigns."  This really does not fit Todium without a lot of mental gymnastics.

The clue, I think, is in the bit about the fourth moon.  Tanavast describes it as "in splinters", or broken.  Also, remember the prophecy from the lighthouse keeper: They’ll come with Light in their pockets. They’ll come to destroy, but you should watch for them anyway. Because they’ll come from the Origin. The sailors lost on an infinite sea.

This all aligns with the fourth shard at the Origin theory, where at the end of Era 2 the fourth shard, from the broken moon, will reign over Roshar.