The three stages he went through.

Step 1: The Astral Alignment. 

He calculated the positions of the planets, believing that the macrocosm of the heavens dictated the microcosm of human history. 

Step 2: The Trance. 

Through meditation and the smoke of burning laurel leaves, he would enter a state of sensory isolation, allowing the images to flood his mind—shattered shields, burning cities, and kings without heads. 

Step 3: The Obfuscation. 

He feared the Inquisition and the wrath of men in power. To protect himself, he wrote in quatrains—four-line verses—cloaked in a deliberate, cryptic mix of French, Latin, Greek, and Italian. He shrouded his visions in metaphor, ensuring they could only be decoded by those who lived through the events he saw.