You can drain or give your chi to others. Giving your chi will empower and heal them, while draining the chi of others will harm or even kill them while strengthening yourself.
At the cost of a whole person’s worth of Chi, you can bring back the recently deceased. They will be weakened and require daily chi from you for at least a week.
Note that giving your chi will weaken you, and if you don’t have enough chi you will die.