Patch notes claim Anti-Mage's Mana Break was reduced from 28/40/52/64 to 25/30/35/40. This wasn't changed ingame, instead the max mana burned was changed from 2/3/4/5% to 1/2/3/4%.

Additionally, his agility gain was reduced from 3.2 to 3.0 with no mention in patch notes.