A game for 4 year olds

[Iscah]

In Zodiark's case, the aetherial currents he had weaved into a barrier around Etheriys immediately corrected themselves and started to induce aether sickness in wildlife as a minor side effect of the aether levels on the surface increasing.

I don't have quotes to back it up, but my impression was not that Zodiark rerouted the currents but is actively emitting a planet-wide shield to prevent the weak points from being an issue.

If that is the case, then with his destruction, the shield is gone and the weak points are again letting Meteion's assault through. Nothing else needs to have reverted to an earlier state for the situation to change.