stinging lash weapon in main hand
black light weapon in offhand

Demon can be hurt by the lash, but is immune to the black light

I eyejab the demon, and can't learn the naunces of it since hes immune. Is it because ONE of my weapons hes immune to, or is it because for some reason I'm using my offhand weapon to do the eyejabbing, or is it some sort of other bug, or by design?

Short log:
<hp m mv>k demon
Your stinging lash EVISCERATES a minor shadow demon!
A minor shadow demon has a few scratches.

<hp m mv>
You parry a minor shadow demon's bite.
You dodge a minor shadow demon's bite.
You dodge a minor shadow demon's bite.
A minor shadow demon dodges your stinging lash.
A minor shadow demon parries your black light.
A minor shadow demon has a few scratches.

<hp m mv>eye

<hp m mv>
You bring the handle of a twined evergreen flail about, but miss a minor shadow demon's eyes.
You can't learn the nuances of eyejab since a minor shadow demon is immune to your attack!
A minor shadow demon has a few scratches.

n/t