Found here or here, the Impossible Bloodline lists its capstone ability (i.e., level 20 bloodline power) as follows:
The wording regarding bleed effects, critical hits, and sneak attacks is peculiar. For bleed effects and sneak attack damage, I would infer that "no additional damage" would mean taking no damage from such effects (immunity to them, in other words).
However, how Living Paradox is meant to interact with critical hits seems slightly less clear. Of course, it seems plenty clear to me that a character with Living Paradox would still take damage from a critical hit, albeit only the damage that would be dealt by a non-critical hit.
Now, the question: Since Living Paradox seems to effectively grant immunity to sneak attack and bleed, as well as ignore extra damage from critical hits, does it (or should it) confer immunity to critical hits?
(Other input regarding the "no additional damage" clause of Living Paradox in regards to sneak attacks and bleed effects is, of course, welcome.)