If you actually want to use the [Ferrox] in SP something like this is what you want. You want as much base and crit damage as possible to make your Slash bleeds as big as possible. [Primed Firestorm] doesn't affect this weapon despite having an AOE damage listed. Thanks to this weapons awesome Riven disposition we can get some massive crit damage out of it. Put whatever you want in the Exilus slot.

When testing bleeds against lvl190 Exo Gokstad Officers, 1.4 mill is as high as I can get before it just starts killing them on the initial hit.