Remove the buff triggered from dexterity?
Dexterity is an essential mastery and mechanic for this game, however the way it puts players at a disadvantage for nodes like buffet or the Mystic Dispersion mastery is completely unfair in my opinion. Evading specials or baiting specials are very important and unless you have a power control champion it is something that you have to do.
So my suggestion would be either removing the buff triggered by dexterity all together or having it so that it doesn't refresh after one dexterity. This way Mystic Dispersion and Buffet still punish champions that trigger loads of buffs but don't make the game ridiculously hard at times when the AI is refusing to throw a special.