This morph should increase heavy attack speed after casting. But anytime you perform another action you have to do 1 normal speed heavy attacks before the others are faster. Is this a bug or feature?
If I had to guess, the current implementation of the speed buff probably reduces the heavy attack wind down time, which would increase the overall heavy attack speed, but only after the first cast. It would be much better if the heavy attack speed buff applied to the start of the attack, rather than the end.