Divine Wrath

There's a knack called Divine Wrath in Scion: Demigod. I never really looked at it before, not in any serious way. Now one of my players wants it. Problem is, when I look at what it does mechanically, I start to think it's broken.

• It transforms your Grapple attacks into Aggravated Damage.
  
• This means they heal very slowly and few powers can speed that up. I've already decided such powers didn't fit the setting. But without them, is Divine Wrath broken? Most NPCs aren't going to have access to that specific Knack or 7th-level Boon, so it makes no difference. Most NPCs die in battle, rather than escaping to heal later, anyway. Maybe that healing time is irrelevant.
• The more important issue is Soak. A typical Elder (Legend 6) Giant soaks 20 levels of Lethal (24 levels of Bashing) but only 5 levels of Aggravated. So, comparing this to other powers: should 5 XP grant +15 levels (roughly 30 dice) of damage? The answer to that has to be "no", especially when you consider it's adding agg damage to an attack mode that already renders the foe inactive with a DV of Zero.

So, I need to: house-rule Divine Wrath, house-rule Agg soak, or just deny the Knack entirely. And I have to make that decision before the game this Sunday.