I'm a slow reader. I really am.
But I made... conclusions.
I just got to where
and reading about spanreeds got me thinking...
What if you used the same kind of gemstone, but instead of linking it to two reeds, you linked it to a sword and a stick. To be more specific, a storming Shardblade. You could pick up your stick (while standing somewhere with a decent view of a battlefield, with moving room), and fight whole armies. Without even being too close to them all.
Then again, there is the whole "invested VS invested" thing. May not work, idk.