Yeah I know its (very) early, but otherwise if they finalise it and implement it, It'll never get a see through.
I suggest two types of priest magic, Dark and Light. Dark Priests follow moshran, Nargun and partly Cherga; whislt Light Priests follow the other gods.
The 'spells' of Dark Priests would be used for slight healing, but very heavy attack spells, whislt the Light Priests would be able to heal, defend and protect efficiantly. However the (main) suggestion is below.
Since priests follow the gods, it would be a good idea IMHO if we bring the gods into it; so I would use altars as a base for mana regeneration. There would be 3 kinds of alters: Blessed, Ruined and Cursed; and the speed of mana regeneration would depend on the presence (around Gobaith) of these altars. For example, if there are 2 blessed altars, the Light priest would gain X mana /minute; whislt if there were 4, he would gain 2X mana. This would make the altars important, and both sides would want to have a maximum of each altar in order to speed up regeneration. This is where the conversion spells take place.
(ok here's where it gets complex to understand); each altar would have HP, and this HP can go from 100% till -100%. [In order to work efficiantly, you need the 'karma' thing implemented first (ie that of each creature being good or bad)]. A person will be able to add or remove this percentage by either praying, or cursing; depending on his beleif to that altar; when this is done, that person loses all his MANA, and the 'HP' of the altar changes accordingly (very slightly) [+ve if prayed, -ve if cursed]. When the altar arrives at 0HP; it turns into a ruined altar, then a spell 'Curse' or 'Bless' (depending on the priest type) can be used upon it. The spell drains off the priests HP, and Mana, however it converts the altar into a blessed one, or a cursed altar depending on the composure of the priest.
And this would create a sort of 'battle' between the two sides of the coin of priests.
Additions:
1) Hp gain depending on priest skill
2) Altars could even be small shrines in the middle of the forest
3) CHanges would be very rare, so there could be something like (global message: To the south, a large mass of dark energy seems to erupt OR "to the south, a bolt of pure holy energy erupts"
4) Instead of a simple spell, the priest could get teleported to destroy the 'guardians' of that altar
5) Altars lose HP over time, therefore prayers need to be done frequently if that altar will be of any value
6) Altars with a higher HP will help increase global mana faster
7) A priest with low mana will increase his mana faster, draining it from the altar's HP by mistake
Nice animations of blobs circling the altar, spirits depending on that altar.9) Sacrifice?
10) Some altars more 'powerful'
In practice
"Many dark priests are finding that their gods do not favour them enough to give them the mana they require, after the [Insert Light priest group here] claimed the shrine at the temple for their own gods"
"During the battle for the altar in the middle of the forest, the orc band crushed the defenders, claiming the altar for their own use"
"The elves of Vanima are distraught at the sight of their shrine being used for the dark arts; and are calling for the Paladins of XXXXXX to help restore the altar to its former glory"
Programming
Pseudo-code
Manaregeneration := MODULUS OF [Skill used] * [stats] * (amount of altars to your faith)/(total amount)
or
Manaregeneration := MODULUS OF [skill used]*[stats] * (total amount of altar HP)/total amount of HP possible)
*Deep breath out*
SO, what'da think?
