On the surface, the clash should have been entirely one-sided, especially on purely physical terms.
The mana had replicated one of the Great Old One's siblings, creating a beast that was bigger than what Khan had defeated in Coravis. The creature wasn't quite planet-size, but its stretched body could probably come close to connecting the surface with the atmosphere's highest point.
Meanwhile, Khan was only a tiny man. For all intents and purposes, he was less than an ant compared to that gargantuan creature. The latter's scales alone were many times his size, suggesting a sheer impossibility of a fair and proper physical clash.
The shockwave the gargantuan snake generated when its head sprang forward highlighted that immense, apparent gap. The creature's mere movement was akin to a natural catastrophe. Its simplest physical functions could alter a quadrant's topography, making weaker forms of life inconsequential.