Does this reverse the Mikado, ect -Fury of the dark lord rulings?
Previously cost reductions that are still on going. (such as mikado having -2 gold cost while you had a scorpion clan courtier in play) Stayed in effect.
Cost reduction rulings.
A topic from AEG's L5R CCG Rules forum, copied for Oracle of the Void from the Wayback Machine (its copy), so posts it didn't save are missing. Players' names are left out; the rules officials are named. Rulings are as they stood on these dates; later rulings, the rulebooks and the Rules Archive may differ.
Does this reverse the Mikado, ect -Fury of the dark lord rulings?
Probably not. Effects that have specified duration (continuous reductions from strongholds) are still continuous. (Edit: Fixed.)