So, if I'm a caster who has both these feats, can my Cord of Stubborn Resolve keep trading my fatigue for 1d6 non-lethal?
Flumefire Rage
Source Elemental Master's Handbook pg. 7
Your meditation before a rune-engraved stone in the Flume Warrens unlocks the secret of its blazing flame.Prerequisites: Cha 15; bloodrage class feature, elemental focus class feature, or Varisian Tattoo (evocation) (Pathfinder Campaign Setting: The Inner Sea World Guide 289).
Benefit: When casting an evocation spell that deals fire damage, you can deal +1 point of fire damage per die. If you do, you must succeed at a Fortitude save (DC = 15 + the spell or blast’s level) or become fatigued. You cannot use this feat while fatigued or if you cannot become fatigued.
If you are raging (such as when using bloodrage or affected by the rage spell), this damage increases to +2 points per die and you roll twice when attempting the Fortitude save and take the better result. This feat does not otherwise grant you the ability to cast spells while raging.
Raging Blood
Source Advanced Class Guide pg. 155
Your blood boils with latent energy, filling you with an intense fury.Prerequisites: Eldritch Heritage or sorcerer bloodline class feature.
Benefit: You gain the 1st-level bloodrager bloodline power for your bloodline. In addition, you gain the ability to enter a state similar to (but less powerful than) a bloodrager’s bloodrage. You can enter this lesser bloodrage twice per day, for up to 4 rounds. During this lesser bloodrage, you gain a +2 morale bonus to Strength and Constitution, and no morale bonus on Will saving throws. Otherwise, this benefit is the same as the bloodrage class feature.
If you have more than one bloodline, you choose the bloodline this applies to upon taking the feat.
Cord of Stubborn ResolveAura moderate transmutation; CL 8th; Slot belt; Price 15,000 gp; Weight 1 lb.
DESCRIPTION
When fastened about the waist, this stout length of rope grants a +2 enhancement bonus to Constitution along with prodigious stamina. Treat the enhancement bonus to Constitution as a temporary ability bonus for the first 24 hours the belt is worn.
Any effect which would cause the wearer to become fatigued deals an additional 1d6 points of nonlethal damage instead. Any effect that would cause exhaustion likewise causes 1d6 points of nonlethal damage and leaves the wearer fatigued instead of exhausted.
Flumefire Rage has:
"You cannot use this feat while fatigued or if you cannot become fatigued."
pretty sure the feat won't work with the cord on.
pretty sure the feat won't work with the cord on.
Agreed. While you can still become fatigued through other means, if the Flumefire Rage feat cannot fatigue you, it renders the feat inactive. Just lean on the rolling twice while raging and boost your fort saves vs fatigue as much as possible.
DC is max 24, even a sorcerer will have a minimum +14 (+6 base, +5 cloak of resistance, +3 belt of con) by the time they get the ability to cast 9th level spells. Rolling a 10 on 2 dice is just shy of 80% likely to happen; just buy a wand of lesser restoration for between fights when it does fatigue you. Easy ways to push it of course is pumping con at chargen, Great Fortitude and other traits for +1 fort, the raging blood giving you +2 con, luck-items, etc. Getting your save to +19 or better means that with the reroll you have a sub 5% chance to fail (less than rolling nat 1 on a single die), and that's only when you cast 9th level spells.
If you're a bloodrager, you don't even need to try to pass, by the time you can have 1st level spells, you'll have a minimum +10 on a DC 16, meaning 6.25% chance you fail.