How to proceed with Raise Spectre

So I'm looking at what to progress towards on my Raise Spectre Necromancer.

It currently feels fine for the most part, but I would like to see if I can push the damage further in some way (outside mirroring items)

I have about 250-300 divs to spend. But I'm racking ny brain trying to puzzle out an upgrade path. Is anyone playing this who has any ideas on how to proceed?

Here's my pob: Level 98 CI Raise Spectre Necromancer [3.26]