Hideous Blow Damage Doubt

[Theodore01]

If you successfully hit with your melee attack, the target is affected as if struck by your eldritch blast. This damage is in addition to any weapon damage that you deal with your attack, although the eldritch blast effect will NOT trigger if no damage is caused by the weapon itself.


It's totally unrelated to your weapon. (Activating HB adds +1 unresistable damage to your weapon. )

After you hit you'll see a separate damage number in your combat log. (blast dices + essence-modifier (if any))
HB damage does also not double on a crit.

[EasternCheesE]

You can consider hideous blow as a separate eldritch blast that hits your enemy (which can't crit) when your strike connects. As previous responder said, it's separate and doesn't account any weapon stuff.