Tell him to use hurricane in solar up until 2 sets of adds are dead. When on final set use standard rotation and dot up the last 3 adds.
So pre plant mushrooms, start 1 cast from lunar, pull timer, use potion, pop starfall, cast starsurge, pop Incarnation/Vigil, pop starfall again, use astral storm until 16 seconds left on Incarnation/Vigil, pop CA, pop starfall, detonate mushrooms, dot spam until 2 seconds left on CA then finish with hurricane/astral. When that cast ends push towards solar and maintain hurricane until 2 sets of adds are dead.
If he gets hit with an amber trap during all of this his dps will fall off the earth as you have interrupted a brutal dps rotation that is unforgiving
Enjoy.