With the Episode 1 release there were a pair of mesmer changes missing from the initial notes as we unable to get them translated in time for all languages; these notes'll be in a bit later:
Imaginary Axes: This skill can no longer hit the same target twice with the same axe.
Mirrored Axes - Phantasmal Seeking Axe: This skill can no longer hit the same target twice with the same axe.
Damage from these axes hitting multiple times on individual targets was blowing out mirage damage. These changes should help get Mirage characters from unreasonably high to back to reasonable high damage, but we'll continue to keep an eye on their sustained and spike damage moving forward.