Originally Posted by
Riv
The healer is one of my favorite units in the game, if not my absolute favorite.
Some things to know about her would be:
She can only heal ground units.
Her heal spell is ranged.
Her heal does a small aoe and is great for neutralizing splash damage on groups of troops, as long as the splash damage does not 1 shot your troops.
Unlike the heal spell, her heal effects heroes. if you have a damaged BK for example, if you can get her to heal the BK to full health, he will be available for the next battle without requiring any sleep.
Healers can be used on defense, although this is generally not advised, and she will heal buildings.
Most importantly,regarding her AI, she will always path towards the nearest unit who is still alive and missing health. Once a unit is fully healed, if they do not take damage in the next second or two, she will begin flying towards a new unit to heal. You can essentially guide her by deploying troops nearby, in range of a defense (so they take damage) and she will start going their direction. When you get the hang of it, you will start to realize just how useful she can be.
She can get "confused" and bounce back and fourth between two groups not healing anything if her nearest target keeps dying right before she gets there. This can be avoided if you add a few troops to one of the groups as she arrives so that they will not be dead by the time she arrives.