Dominions 3: The Awakening/Magic/Communions

Tips

 * Regen for slaves (use Shroud of the Battle Saint with a N-bless or Rings of Regeneration) can sometimes be much better than reinvigoration 5 for slaves.
 * Alternatively get a master to cast Soul Vortex, so the slaves all Soul Vortex each other + their chaff guards. Soul Vortex only saps 1HP from each neighboring unit. Spaced apart, each slave could have 5 regenerating guards (trolls, werewolves, blessed Flagellants, etc) to act as the hp source. Just E4/N4 bless would give you +12 reinvig per turn with 5 guards, and if you can pop on Summon Earthpower you're at +16 reinvig for happy casting.
 * Priests with only H-path magic get boosted by a Crystal Matrix per normal, but a Crystal Shield has no effect. To benefit from Crystal Shield, the master needs at least one level in non-H magic. However, a Crystal Shield bestows 8 base fatigue even to 0-fatigue holy spells, so using one for holy communions might not be the best idea anyways. A bug allows an H-only priest with a Crystal Matrix to multi-cast spells in the same round = number of H-only slaves.