Ignore Def % Limit?

There's a difference between PDR, MDR (maybe - I didn't know MDR existed), and physical resist (like elemental resist). Some mage skills have physical element - Evan's Illusion comes to mind, as well as Magic Claw - that is affected by the physical resist of some bosses like Hilla, Epinea, Pink Bean, and Empress. Battle Mages use Dark element.

battlemage has no element

where does it say it has dark element?

all battlemage skill is non elemental and since battlemage has no elemental decrease it dmg will be decrease by 50% when attacking physical strong type

I thought Evan's Illusion was dark element too?

no evan illusion has no element
the only dark element evan has is dark fog and killer wings there might be on more i think phantom imprint has dark not sure on that one