I played Hakdu (cloud giant) and Raeth (felar)

NO METAL - EVER. Even a metal ring will make you fail camo (which there is no echo for failing) also it will make you fail to creep etc. The penalties for ANY metal gear are severe. Always natural materials.

The savage ambush bonus applies to onslaught. Onslaught ambushes are further boosted by using a spear - I highly recommend using a spear.

When it comes to ambush, you care about weapon average damage more than anything else. Damroll is just icing. Ambush amplifies the dmg average and damroll is added after afaik

Smearmud - remove all your gear, smear mud and then wear it all again. It only checks what you are wearing at the time of smearing mud, and not after (likely to be changed after me posting this - potentially it already was).

Skills smear mud gives you huge protection (evade style) to:

Kotegaishi
Kansetsuwaza
Bash
Strangle
Bearcharge
Assassin Kicks (certain ones definitely, maybe all)
Throw
I think it helped me vs entwine once - would need to verify
Lash

must have edges:
LODESTONE LIGHTNING - this is your bread and butter across all builds. Your whole build will revolve around burst damage, being able to hit an annih/errad lightning bolt after an unspeak ambush is awesome.
X hatred (I always go with human, while the most expensive it also boosts your dmg vs all halfbreeds)

if human (roll strength not dex):
Ambush Focus
Power Ambush
hatred edge

Felar - do what you want. I'd not take deft ambush again.