I suddenly deeply understand all the DPxDC headcannons that kryptonite is crystalized ectoplasm. Like, at first I was like "Oh yeah, bc they're both green and semi-glowy(?) and it's a fun plot point for the crossover!"

But now?

In Smallville it straight-up gives people powers. And not just any powers, but powers associated with whatever that person happened to be exposed to/obsessed with at the time of exposure! It's extremely emotionally reactive, just like (headcannoned) ectoplasm!!

It all makes sense now!