I don't know if it is intended but you can use the skull while auto-attacking with a wand.
I doesnt work the oppsite way though. If you try to auto-attack while using the skull, it won't work.

In my opinion it's kinda op and I don't think it is intended to use the skull while auto-attacking as you can constantly reduce your cooldowns.

@all players who are using this bug/exploit: please don't hate me