Question about lightbringer

Sorry if it is already posted, but I don't see anyone explain this when i searched. is the lightbringer extra damage only with attacks? or does spell work too. I dont have a ele or necro at the point of th game yet if someone know the answer can you point it out? Thanks.

All direct damage, including spells.
It does not affect non-direct damage such as Spiteful Spirit and Empathy.

Nor does it affect Life Stealing.