From Event 7.
I didn't get screencaps, but here's some info in summary:
Halcyon Boots:
Changed from 100%/2SP to 5%/15SP. Although this sounds weaker in a vacuum, it's probably stronger in practice. Still this part of the item is weaker than Concordant Opposition let alone Transform Kinetic Energy.
Skybreaker:
Two changes:
First, it does more physical damage now. 2.5[3d6].
Second, the 'Skybreaker' mutation was toned down a little (3d6 all bursting instead of 5d6 all bursting).
Overall the weapon is better but not by much, it still needs some better form of Lightning Strike proc on it to be of any use except on the rare 'i take additional damage from electric damage and have high fortification' mobs.
There were probably other changes too, I didn't look too closely. None of the changes were huge.