Tantra is cumulative system which contains multiple mantras. Now the mantras have their own power, energy, and effects. The mantras are so complex as energy entities that they manifest as visual images of deities so that human beings can understand what the mantras can do.

Fair. But also, additionally, when you're chanting the mantra, you will have an image of the deity that will be told to you. You meditate on this an image.

It helps. To get the mantra to work even quicker.