Iron Lungs: Humans recover from fatigue faster than other races. They regain full HP on a Short Rest.
Adaptable Mind: Humans can choose one weapon proficiency and one skill proficiency of their choice.
We Stand Together: Humans can use the Help action as a Bonus Action.
All three of these are really interesting, and I especially love "We stand together". I don't know how the aid action has been implemented, but supporting others is my favourite role and would make the human, a race that I usually discard by principle, something I'd really have to try.
