All about Secret Catalyst of Dwarven Royal Family and Ultimate Restoration Stone of Dwarven RF.
In normal fortification the success rate is always 50%, if you use these catalysts. If it fails, you just use the restoration stones and repeat.
Light fortification success rate:
90% Success for dimly shine
30% Brightly shining
10% Cold shining
You can get them from daily gift boxes. Catas on wendsday and restoration stones on saturday.