[Finalgenesis]

One of my attempts to cast reinvigorate in communion involves half a dozen mages casting sabbath (no matrixes are involved), on casting sabbath my slaves and master racked up a bit of fatigue, followed by a round of spells then reinvigorate from the master in turn 3, by then the fatigues were above 50 for the master who should be casting reinvig next. The reinvigorate didn't go off, instead I get imps (It's always the damn imps!), enemy had a forces of 50+ units. Suffice to say the round 5 reinvigorate didn't go off either, let's just say the battle did not go my way.

I'll admit I only tried two more times afterward half heartedly, then gave up on the spell in disgust.

I believe you are right on the fatigue, but it must be something else preventing my mages casting in this case.

Good tip on the communion master not being able to use gem boost.