Originally Posted by
Shirofune
No, you're doing it wrong.
Fel Rush and Vengeful Retreat should NEVER be used together, as the momentum buff gets refreshed, and thus, you lose uptime.
Fel Rush, unload your skills, wait for Momentum to wear off.
Vengeful Retreat, unload your skills, wait for Momentum to wear off.
That's basically it.
And yes, you should be using both charges of Fel Rush if you want to maximize Momentum uptime (=DPS), just don't use them together. The order usually is Fel Rush -> VR -> Fel Rush.