During the Phyrexian Invasion, Darigaaz joined forces with the planeswalker Tevesh Szat to fight the forces of the dark lord Yawgmoth.
Facing the threat of Dominaria's defeat at the hands of Phyrexia, Darigaaz and Tevesh Szat awakened four of the legendary draconic Primevals—Rith, the Awakener, Treva, the Renewer, Dromar, the Banisher, and Crosis, the Purger.
Darigaaz then learned that he was actually Rhammidarigaaz, a word meaning "conception" in the ancient dragonic tongue—that he was the fifth Primeval. All five of the dragons' power was unleashed against the Phyrexians—but a mad rage also gripped each godlike dragon's mind. Having sacrificed many to achieve their power, all five dragon Primevals decided not only to conquer the Phyrexians, but even their allies among the Coalition.
Darigaaz laid waste to both friend and foe, even attacking the skyship Weatherlight. In a moment of clarity he realized the indiscriminate ruin he had caused, and realized he had paid too high a price to gain ultimate power. Darigaaz had only one way to end the destruction—he cast himself down into a volcanic caldera, shattering the power of the draconic Primevals and allowing the Weatherlight crew to survive.
The Apocalypse wiped away almost all memory of the legendary Rhammidarigaaz, and the Primevals retreated into obscurity.