Complex sentence: The player can use whitsever moves as who likes, whenever, as long as there are enough fully-charged action gauges--therefore, if all three gauges are charged, three single-gauge moves can be carried out consecutively with no hold between them.
Split into simpler sentences: The player can use whatever moves one likes, whenever, as long as there are enough fully-charged action gauges. Therefore, if all three gauges are charged, three single-gauge moves can be carried out consecutively with no hold between them.