Whenever a formation transforms, there must be life and death, strength and weakness. This is not because those who guard the formation are merciful at heart, but because the Heavenly Mechanism dictates it so. Without special means, the arrangement must follow these patterns for the array to take shape. The Four Symbols Formation is no exception.
Thus, every ferocious array operates by making the formation continuously shift and transform, striving to completely obscure the thread of life within it. The more it changes and the faster it operates, the harder it becomes to break the array.
The reason True Master Meng said that this Four Symbols Formation is not overly difficult is that it has fewer than a hundred variations. In other words, there are only nearly a hundred smaller formations rotating and overlapping within it. As long as you find the gate with the most vibrant thread of life during each variation, you can pass through safely.
