Persistence

You refuse to let exhaustion, pain, or failure stop you. Even when your body begins to give out, you find the strength to push onward. You gain the following benefits:

Ability Score Improvement. Increase your Constitution score by 1, to a maximum of 20.

Hardy. You have advantage on saving throws against exhaustion.

Unrelenting. When you fail a saving throw, you can reroll it once. You must use the new result. When you do so, you must succeed on a DC 10 Constitution saving throw or gain one level of exhaustion. Each time you use this ability before finishing a long rest, the DC increases by 5 for the next save. The DC resets to 10 when you finish a long rest.