Determination, the difference between the slow and the fast. No one finds momentum before me. No one finds victory before me. Even the world cannot outrun me. I will save those I hold dear before the danger. I wont break, not while I challenge the gods in a marathon of life.

"People try to defy death with medicine and magic, but that only slows death. The real trick is to make us faster... nimbler... quicker... That doesn't just defy death, It mocks it" -Vivian, Elven member of the Eastern Rogue's Guild   

Once per long rest you may become "Determined" and gain multiple effects (this feat stacks with other "Will of" feats)
For the next 6 hours you gain advantage on all Dexterity checks and saves, if you would already gain advantage on Dexterity checks and saves without this feat you may instead double your Dexterity modifier. After every successful Dexterity check or save, you gain an extra Reaction in combat. After the 6 hour duration, you get disadvantage on all Dexterity checks and saves and your speed is halved until you take a long rest.