This is just an idea that came up as I was theorizing with some friends, don't know how possible it is with knowledge we have from WOBs and the like, but thought I should put it out there.
I'm pretty sure there's been a bunch of theorizing before that Honor and Odium could combine to become Vengeance before. The way I see this working is that vengeance is kind of like oaths/promises that are fueled by hate. Anyway, we were theorizing about who would make a good Vessel for the shard, and Moash just fits too perfectly. His entire storyline thus far is driven by vengeance.
So. Is it likely that if such a Shard were to exist in the future that Moash would become it's vessel? Smart people feel free to prove me wrong (or right ).