The extreme passion rooted in a desire to protect what you care about gives you strength at the brink of death. As a reaction, if you would normally be reduced to 0HP by an attack, instead be reduced to 1HP and enter Determined Stance. Upon entering Determined Stance, all of your class specific resources (action surges, ki points, etc) are restored to their maximum. While in Determined Stance, all attacks that you make do their maximum amount of damage. You also cannot drop below 1HP while in Determined Stance. Determined Stance lasts for 3 turns, and at the end of your third turn you can choose to extend your Determined Stance by a max of 3 turns by making a CON save (DC:15). When exiting Determined Stance, you have two ways to exit:
Last Resort: When exiting Determined Stance, you take all of the damage you dealt in this combat (including damage during Determined Stance) and deal all that damage to one target. This attack ignores resistances and immunities, but will instantly reduce you to 0HP, and if you decided to extend Determined Stance by any additional turns, the number of turns that you extedned by will affect how severely your body is injured. For example, extending by one turn will cause your body to sustain extreme damage, requiring 8th level healing spells to restore to regular functionality, extending by two turns will cause your body to sustain even more extreme damage, requiring 9th level healing spells to restore, and extending by three turns will cause your body to sustain damage that cannot be healed by any means.
The Quiet Way: When exiting Determined Stance, you take all of the damage that you took during Determined Stance all at once (Ex: You recieved 30 damage while in Determined Stance, so when exiting Determined Stance this way, you take 30 damage.)