Vraegar's abilities were enigmatic, and Rowan built it in a manner that would take advantage of all the advantages of his powerful Empyrean body.
His scales were harder than Davross, gearing closer to the density of his Empyrean Adamant with every day that passed, his claws were sharp and his movements were swift, he would be a force of devastation when he attacked, and so Rowan saw no need for the Dragon energy attacks to do more of the same thing, instead it was to focus on other things, namely spirit, and vitality.
Vraegar energy-based attacks were not destructive, instead, they acted as a form of devouring force that consumed energy, vitality, and even Spirit.
When Vraegar's blow had clashed against the Tribulation, it did not fight fire with fire, and it appeared that it had been destroyed, but that was far from the truth, instead, it went the opposite route and absorbed the energy from the attack.