Paired with tier-3 Unkillable in the "Conjured Servant" metatrait
http://www.sjgames.com/pyramid/sample.html?id=5583
Also works with Supernatural Durability
http://forums.sjgames.com/showthread.php?p=104933
All at standard costs, so it's 100 total for either combination.
It could work with tier-2 Unkillable also, I don't know there'd be a point to tier-1 though. Automatically failing your HT rolls overrides the benefit of ignoring them.