In regular way, Carnage dont proc Avenging Storm : it is not a weapon attack. But there is one weapon that can make an effect (static charge) using abilities that use the weapon as component.

Lord Darryn's Voulge cause Static Charge on carnage, and it is a weapon feature. Every enemies in the Carnage area take the stacking effect / lightning damage on crit, even on top a disoriented weapon effect on crit for the Barbarian upgrade.

With Avenging Storm, that mean a Lightning Carnage.

 

Of course, there are some weapon like Amra, Keeper of the Flame, Mortars, Citzal's Spirit Lance etc causing in AoE Avenging Storm, but for the Darryn's Voulge, that is different :

Each time Static charge is applied, one lightning proc. For each 10 shock damage/ stack on crit, one lightning proc. Also for the disoriented effect. That mean, again, Lightning Carnage.

 

This is interesting as i'm looking for ways to get the most out of Heart of Fury, though not Tempest related since need to be SC. 

As HoF triggers carnage, cast Avenging Storm (from item) and use Lord Darryn's Voulge.  Should be a real lightning show!  Only problem is my SC Barb is godlike so no helmet for Avenging Storm unless I restart!

46 minutes ago, summatsupeer said:

This is interesting as i'm looking for ways to get the most out of Heart of Fury, though not Tempest related since need to be SC. 

As HoF triggers carnage, cast Avenging Storm (from item) and use Lord Darryn's Voulge.  Should be a real lightning show!  Only problem is my SC Barb is godlike so no helmet for Avenging Storm unless I restart!

I try for give you an overview of HoF + Darryn's Voulge + Avenging Storm, this is pretty devastating. For my concern, I dont really understand why HoF cost 4 rage and Whirling Strike 3 bonds, but this combination is really powerful.

Clearly HoF is overpriced in the game, making it usually not worth selecting. But thanks for pointing out a creative use of it, @Constentin Lévine! As for godlike MCs, just invest in arcana and cast AS from a scroll. While scrolls seem expensive, for most of the game you'll have plenty of money and can afford this if you wish. I personally prefer doing this, as it is much faster (the cast time for the helmet is long), and arcana gives you a nice boost to the spell's power.

HOF should maybe have a talent upgrade which lowers the rage cost by 1. I feel like that still wouldn't be overpowered considering how strong some of the other Barb abilities are like Barbaric Retaliation 

7 hours ago, Constentin Lévine said:

For my concern, I dont really understand why HoF cost 4 rage and Whirling Strike 3 bonds

I guess on could argue that some Barbarian abilities are a bit more expensive compared to Rangers' because Barbarians can regain some Rage with Blood Surge - while Rangers have no refund mechanic at all. Bu then strong Barb stuff like Driving Roar or Dazing Shout only cost 1 while Heartseeker costs 4.