Final stand(not busted)

You have trained and have gained brilliant resilience. This grants you the following abilities:

• Add 1 to your Constitution score, to a max of 20.
• When you drop to 0 health points, you will not be knocked unconscious until the end of your next turn, enabling you to take a full turn before being knocked out. On this turn, you gain advantage on all attack rolls. Once you use this ability, you cannot use it again until you have completed a long rest. 
• However, if you take any damage between these two turns, you must make a Concentration save to see if you maintain consciousness falling unconscious on a fail. You can add your constitution modifier to those saving throws