Introduction to communions Edit
Communions are a tactic used by mages to allow them to cast more diverse, powerful, or numerous spells on the battlefield. They are typically formed of astral or blood mages, as the spells to set up a communion are found in only those two paths.
One or more mages are communion masters. Their spellcasting fatigue is distributed to the communion slaves, and they gain a boost to all their magic paths (including holy) based on the number of communion slaves.
One or more mages are communion slaves. They cannot act, but they all gain the effects of single-target buffs cast on any master. They absorb fatigue for spells from the communion masters. If their fatigue reaches 200, they will start taking damage instead, and may die.
A valid communion is formed when there is at least one unit with the 'communion master' ability and at least one unit the 'communion slave' ability. These can be acquired via the spells Communion Master, Communion Slave, Sabbath Master, and Sabbath Slave as well as the items Crystal Matrix (communion master) and Slave Matrix (communion slave).
Communion masters gain log2(n) (rounded down) path boost, where n is the number of communion slaves. For example, a communion with 2 slaves provides a boost of 1, 4 slaves a boost of 2, and 8 slaves a boost of 3.
Fatigue for each spell depends on the master casting the spell, as well as the communion slaves. First, calculate the fatigue the spell would cost at the master's level, taking into account the power increase from communion master. Then put that value into the following formulae as 'spell fatigue'.
Master Fatigue = (spell fatigue + master encumbrance)/(number of slaves + 1)
Slave Fatigue = master fatigue*modifier
Modifier is a value which depends on the magic skill of the slave (in the primary path for the spell cast) compared to the magic skill of the master. If slaves have random paths (or if you're using a mix of astral unit as slaves), this modifier can vary between slaves, resulting in unequal fatigue distribution.
slave level = master level: 1
slave level > master level: 1/2
slave level < master level / 2: 4
slave level < master level: 2
When determining the modifier, boosters (including booster spells such as Pheonix Pyre) can affect the slave level and master level. Bonus magical skill from communion master will not.
Tips for using communions effectivelyEdit
Many spells gain greatly improved effect with higher magical skill. For example, Maws of the Earth increases in both area of effect and damage, making it a highly desirable spell to cast when you have a large communion backing you.
Spells that only target the caster (ie, reinvigoration) will propagate to all slaves, although it will not affect any masters who do not cast it themselves. This has certain excellent uses.
Reinvigoration (B1 Blood 1): This spell wipes out all fatigue on the affected units. This can be a great way to offset fatigue cost of battlefield spells, but is not practical past turn 5, as the spellcasting AI is not smart enough to continue using it and will happily fatigue your slaves to death.
Summon Earthpower (E2 Conjuration 3): provides reinvigoration 4 even if the slave has no earth magic skill.
Power of the Spheres (S1 Conjuration 3): Casting power of the spheres on one master can be a very efficient method to reduce communion fatigue. If you are using the same mage type for masters and slaves, your slaves will now have a higher skill than the masters. Looking at the modifier table, this will result in half fatigue for the communion slaves (expect from the master who cast power of the spheres).
Personal Regeneration (N2 Enchant 3): Allows your slaves to regenerate. This will reduce the chance of burning out your communion significantly.
Things that could use testing Edit
Magic resist and Communions - I expect that path boost via communion will result in spells that are harder to resist, but it remains untested.
Path boost via communions provides the same pen bonus as other methods of raising paths. (+1 pen/2 levels).
Video Tutorial Edit
Communion Tutorial as EA Marverni Playlist [Tutorial courtesy of iSeenUB4]
The playlist features Communions using EA Marverni. It consists of three episodes. the first being a pretender creation and expansion and further explanation, and the last episode being a fairly large battle with a Communion put in practice.
Sample Script used in the Video
Master: (Cast Communion Master) (Summon Earthpower) (Battlemagic)
Slave: (Cast Communion Slave) (Holdx5)