If you corrupt an item to have "culling strike" that cull works with any spell like ball lightning but doesnt work with minions.

Does culling strike work with spells?

Supports non-instant spell skills. This is a Support Gem. It does not grant a bonus to your character, but to skills in sockets connected to it.

Does culling strike work on bosses?

Culling strike does work on rares and bosses. It works on everything.