There are different strategies which can be used in a battle between creatures.
Using crafting technique one can do an energetic barrier. It would act as a physical barrier not allowing to pass further, separating the energies and not allowing them to interact, even is the creatures are close enough for it.
It can hold a while even if energy levels of the opponents are not the same. But on a long term, the one who has more energy would be able to break the barrier.
While all of the energy exchange happens only on a close distance, going away would break the flow. Allowing to escape and hide. But the other creature might choose to chase and follow, which can make running away a complex task.
Creatures who have friends can release a call asking them to unite. When friends are coming close they unite into one, making a more powerful creature.
When opponents are physically close they can use any of the energy exchange techniques to win the battle.
Usually pure creatures, like Aery, would use giving energy. And dark creatures — taking energy.
While giving energy to a dark creature it acts as becoming one with it. But because the other creature is dark — light creature would start feeling all of the dark creature’s pain. And the pain is so immense and you feel it as your own, that it is very hard experience for a light creature. And one naturally would want to run away or to use take energy technique to get back own energy.