Malevolence is a sort of...spiritual impurity that happens in the world. It's in everything, but it should be manageable to deal with if you can find a balance. If you don't it can cause disasters and wreak havoc on everything. The seraphim can help to maintain the balance that's needed so that the world doesn't fall into chaos.

[he tries to find the right way to emphasize the words, but shakes his head a little when it falls flat in his ears]

It's a little convoluted from there, though. I can't explain it very well.