@Daishain: Spirit combat in regards to taking and giving damage goes as follows (as far as I can find):
-Spirits generally deal bashing damage unless their nature allows them to give lethal damage (clawed hands ect) .
-Spirits that are two ranks up on another spirit act as their target's Bane, causing aggravated damage. This is how HWOB was able to steam roll King Sky and Immovable. Fortunately neither spirit lost all their Essence and both can/will come back
-Physical attacks on a manifested spirit only do bashing damage even if they would be lethal. This is explained as being due to spirits having no internal organs to damage.
-Uratha who out rank a spirit do serious damage to their enemy spirit. This is per side bar on page 186 (tooth and claw). This side bar is incredibly vague, but I assume it means they do aggrevated damage... but that said it is pretty unclear if you have to outrank the spirit by 2 levels as if you were a spirit yourself. That said HWOB is Rank 4, meaning you would need 19 points of Renown to even be one level higher.

Because of this, I could find no evidence that says Uratha's claws or teeth ignore spirit rules and do lethal damage. I did find a side bar that states that teeth and claws still do L damage to vampires... but I'm not convinced this applies here.

... Sooo, I recommend you all start using that liquid bane