Relevant feats:
Killing fuels your rage.
Prerequisites: Half-orc or orc, rage class feature.
Benefit: When you are raging and your attack reduces an enemy to negative hit points or kills it, you regain 1 round of rage. You may only use this feat if the fallen enemy had at least as many Hit Dice as you. You can only gain this benefit once per round.
Horrible wounds, whether on yourself or your enemies, make your blood sing.
Prerequisites: Half-orc or orc, rage class feature.
Benefit: When you are raging and you confirm a critical hit with a melee weapon or a critical hit is confirmed on you (whether by a melee weapon, spell, or ranged weapon), you regain 1 round of rage (up to your maximum for the day). You can only gain this benefit once per round.
Every killing blow gives you a surge of vitality, further fueling your rage.
Prerequisite: Greater rage class feature.
Benefit: While raging, whenever your attack reduces your opponent to –1 or fewer hit points, you gain 1 extra round of rage for that day. If that attack was a critical hit, you gain 1 additional extra round of rage for that day. Whenever you rest to renew your total number of rounds of rage per day, any extra rounds you still have from this feat are lost.
So, seeing as the top two of these have "you can only gain this benefit once per round", are they referring to "this specific feat's benefit" or "regaining round(s) of rage" benefit? If it's the former, how would this interact with Raging Deathblow?
Designing up a half-orc Bloodrager who is a.... Very, very angry little lizard... Very angry. Gear and feat selections structured for regaining as much of his angry draconic rage as possible.
I would say you can't benefit more than once from the same action source. That is to say, you couldn't benefit from both Gore Fiend and Thrill of the Kill to restore two rounds of rage by scoring a critical hit which reduced the enemy to -1 hp.
I'm not even sure if that's correct parsing or not.
Honestly though, once you get to higher levels I've never had a problem with having enough rounds of rage for a day. I wouldn't take all three feats. Try one and go from there.
It means "this specific feats benefit". There is no cross reference or way of cross-referencing. Gore Fiend and TotK have no way of knowing the other triggered. Each ability only cares about itself. IF you score a critical that reduces a foe to -1 hp all three trigger.
If there were a universal rule that stated you could only regain one round of rage each round then my answer would be different, but as far as I am aware no such rule exists.
