A few suggestions. Octapus Overlords are severly underpowered atm, still very cool (IMO their the coolest religion in the game) but they went from one of the best religions and a good one for every race to use, to the second worst for war waging (Unless your fighting with a LOT of water) I think that they should have more on land abilities, I understand their a water based religion, but they should have some more land viability.
Drowns SUCK, their cool and all and do more damage than warriors and can also walk on water, however their cost is rediculous and completely pointless to build when you can build a cheaper warrior, you can build a little under 3 warriors per drown.
OO needs a religion specific civic, they are so twisted and different from other religions, (excluding ashen vale LOL) it just seems fitting to have a civic for them and them only. Also a building that allows all living units to waterwalk regardless of class would be fitting. (maybe just add that to the civic)
Stygian (or whatever) gaurds are cool and while being only 1 strength stronger than maceman, they can not only walk on water but also heal themselves in the process. They work great.
Lunatics (BLEH) once a great unit is now terribad. They have an average strength,terrible defence and a crappy special ability now, what used to increase your offence by a great ammount, increase movement and drasticly reduce defence every other turn (50% chance) now gives you a WHOPPING 20% strength, 1 extra movement, and a 3% chance to turn into a barbarian every turn. Which makes this unit, WORTHLESS.
I have 3 proposals to fix lunatics. 1.) Put them back to their original state. 2.) Make them a heavy shock troop with terrible defence and high chance of turning into barbarians, for example make strength 7 def 4 (no defencive bonuses), and a 50% chance a turn to gain 2 additional movement points, 25% strength and ignore ALL defencive bonuses gained by an enemy when attacking which would make these guys great at attacking cities solo (which IMO is what they should be, city shock classes) but have a 30% chance of turning into a barbarian unit when outside of your city borders. (Removed after combat too) These numbers can of course be tweeked.
3.) Turn them into major offencive borderline suicide troops. 8 strength 3 defence 50% chance per turn to gain THREE additional movement points gain blitz and gain 40% more strength, with a 40% chance per turn to turn into a barbarian. Making them the type of troop you want to keep away from your borders at all times, while wreaking havok at the enemies. ALL OF THE ABOVE IDEAS allow the troop to use bronze iron and mithril.
Speakers need to have a better channeling 3 ability, maybe an additional one. Possibly something that doesnt involve water but rather has to do with twisted and or cruel actions.
Anyways those are my ideas, I have one more sugestion, it would be awesome if each religion had their own special T4 unit, tarquline (I think thats the name) had a GREAT mod that did this, adding special units for all religions. This would add more flavor to the game and improve it overall.
Thanks for reading.
EDIT: I forgot to metion a few things. There was a GREAT mod created (it doesnt work with the newer version of FFH2) that allowed the AI to be able to build mages and archmages directly from the city and also giving them free starting random promotions, including 1-5 combat, spell extension and giving them random spell spheres (usually with one sphere maxed at 3) in case you dont know already (some people dont) the AI doesnt know how to upgrade their adepts to mages and mages to archmages properly, they also dont know how and which promotions to give them, which gimps them. This mod completely fixed that problem and its so hard to play without it. I suggest that you make this mod into a official FFH option that can be toggled at the game creation screen (like the blessing of amathon and end of winter ones)
Another thing I forgot to say was summoned units need to have no upkeep cost, seriously. What the hell is a skeleton or fire elemental going to eat? They should be free for 2 reasons. 1. Its logical 2. Its a pain to have to delete summoned units before the turn ends to save on the upkeep cost.