Theurgism doesn't work?

I GM'd it, but I can't see any appreciable difference with Orbs. I still eat 2 charges per use also.

I seen a difference on my all strength giant when I went from lvl 1 to lvl 2. I do not think it increases the orbs ability to do damage but like a orb of holding will be more successful on higher lvl enemies with higher Theurgism. Also my potions like invulnerability went from 24sp to 60sp but didn't make it absorb more damage.