When Walker shot out of the bridge to the elemental planes, the entirety of Genesis felt a potent mana wave cover them before they felt it retract. Walker had been unconsciously manipulating the mana around him in his actions to move well ahead using some of the space mana surrounding him.
When he had returned to the world he had let that control and pressure affect the surroundings, which in turn, caused everyone who could sense it to stutter slightly. This was beyond the royal dragons when they would get frustrated or accidentally release their mana around them.
Then again, Walker could manipulate all the manas and also have an effect on how they all flowed together. They would not be surprised that if he forgot his contour of a moment and let his emotions take over there would be a lot more pressure in general. That among other destructive things because of the pressure from the mana itself.
