To use the teen Titans TA, must at least one of the figures to be damaged (so that it can receive the one healing click), or can it be used as a way to give one damage click to figures liek hawk and dove, who get much better on the second click?
From my point of view, we could give the healing click who doesn`t really need it, so that it would be healed, but nothing would change.
What`s the official ruling about this?

Yes, one must be damaged in order to receive a click of healing from the other.