Quote Originally Posted by Slashley View Post
I haven't really paid attention but... MvP and founder rewards are all Platinum chests, and I don't think that aside from the (non-100%?) founder one, I don't think any of them are Platinum?

So, I don't think that there is any correlation to how well you place in a raid. It's just RNG.
It's definitely RNG, but you simply get more chests if you contribute more to a fight. Usually if I join a fight that's ending I get maybe 4 chests total whereas if I did a lot I'll get 8-12, which means more likely to get more souls. Also as someone mentioned if you're the one that starts it pretty sure you always get one.