We also don't know quite how corruption factors into it. The rules state that the scum can use corruption-based attacks, which is also consistent with the fact that Arjos had the "Dagger of Corruption" on him when he died. That certainly doesn't sound like a nice thing to me. However, all attacks so far show up as elemental attacks of some kind. Or, at least, if there's been a corruption-based attack visible in the write-up I've overlooked it. So, that might mean that corruption just empowers the element chosen for the attack. If so, it's possible that scum could launch a strong attack with any element of their choosing.