Talk:Evileye/@comment-81.167.0.81-20180816074953/@comment-45.56.46.26-20180816222542

Basically, it seems there are things that count as caster levels and things that don't.

There are three main branches of casting, arcane, divine, and spiritual, along with the 'alternative' category (which isn't a branch so much as whatever doesn't go elsewhere). Ainz is an arcanist and his various racial levels (developing from Skeleton Mage) all count as arcane caster levels. Evileye is also an archanist, but her Vampire levels, though they strengthen her stats, don't count as caster levels because they also provide substantial bonuses to melee combat ability.

In short, she can't cast tier 6 magic for the same reason Climb can't cast 3rd tier magic despite being over level 15.