Some time before Ren successfully breached the surface, back when he was still exchanging blows with the dragon and being lied to by the ethereal illusions, even before jamming the crafty and cunning beast barricading his descent, the world outside had not been frozen in place.
When the ancient dragon elongated its physical mass to blanket the lower cavern with a sprawling network of mutant flesh, beginning to absorb the newfound prizes and dominate the spatial fabric of the vault, the mutant horde swarming the surface began receiving a massive influx of power as well.
It happened gradually… A steady, insidious drip of raw ether continuously elevated their baseline threat level while the Vanguard defenders struggled to hold the line, rendering every single clash to maintain the outer perimeter significantly more grueling than the last.
Selphira had managed to anchor the defense remarkably well during the initial phase.
