Jason knew that he had to dominate everyone if he wanted the fight to end.
Because of that, he picked up the strongest Primordial and defeated him with his very own weapons.
With the brightly burning flames of Solaris, Jason showed his supremacy as he kept using his petrification curse, followed by the race specific weakening curse.
Other than that, Jason's physical strength was already far higher than any kind of ordinary god.
After all, his body had been refined and tempered for more than 112 years, and the construct of his Godly foundation was made out of Origin energy.
As he was able to control and replenish traces of Origin energy through his Godly foundation, Jason was able to actively use Origin energy.
And this was exactly what Jason did with Solaris.
He once had read somewhere that the Flame of the Beginning is nurtured and empowered by the Universe's Origin energy.