Burning Resolve (3.5e Feat)
From D&D Wiki
Burning Resolve [Epic]
"You've attacked me enough!"
Prerequisite: Base Attack Bonus +25, Strength 40+, Constitution 30+
Benefit: When you reach half you max HP, You must make a Will Save (Most willingly fail) of 10 + (1/2 ECL) + Str modifier, to not go into a state of Burning Resolve. This state increases your strength by 15, your constitution by 15 and any movement speeds by 15'. To come out of the state you must either be knocked unconscious or be healed over half your (New) max HP. If knocked out, you are fatigued upon waking up and for 3D6 Hours. If healed back over half your (new) health, you become exhausted for the rest of the current day.
Special: When activated, Burning Resolve turned the skin a dark black color and the eyes a burning red, giving it the name "Burning Resolve". In this state, you are unable to speak coherently and also has a red aura around you.