So, I finally played two games with this mod. I used the first version available with Tweakmod. First I played as the Amurites and went for Master of the Elements. Then I played as the Grigori and went for Master of Alteration. I didn't bother advancing farther than that, as the games drag on my computer after a point. I really liked it, and had fun using the new spells and new promotions. I hope this post does not sound excessively negative. I plan on using this mod, I am just critiqueing it. Here are my thoughts:
1) I think there are too many promotions. You don't need "Master of Earth and Air", "Master of Fire and Water",
and "Master of Elements". My suggestion would be to have "Master of Fire and Water/Earth and Air" be granted by the Tower of Elements, or get rid of them and just have Master of Elements. It is a lot of clutter all at once, and this is already promotion intensive.
2) Let some of the promotions come early. Let the first set of "Master" promotions be gotten at Arcane Lore and require sphere 2 instead of 3. This leads to a slightly more fulfilling experience, as the rewards come more gradual (instead of a mass of promotions appearing right at Archmages. That was my problem with point 1, too). Let the "Master of Elements" line be gotten at Strength of Will, and everything else at Omniscience.
3) I am not sure if you are done tweaking these for balance, but I really liked how Master of Alteration worked. It gave two very good abilities that helped at home in a passive way (the trees) and a nice spell for war. It was strong without being excessive, and definately worth the promotions. ...then there was what I got at Master of Elements. It created a unit that was capable of easily (easily!) taking out entire civilizations alone. It wasn't the summon, which was really nice, but the Shooting Stars ability. It reminded me why Meteor was taken out. This spell is just too strong, and with the summon as well, created an uber team that could not be stopped. The fact that the archmage was stronger than normal just compounded things. I cannot imagine what spells could be stronger than that at Destroyer and Omnipotence.
I would reccomend giving each Master of _____ sphere an economic (like the tree) and war (like Might) ability. But please get rid of Shooting Stars, or move it to Omnipotence.
Also, to those that are saying the Calabim or some civ with the Arcane trait are the best for this mod, try the Grigori. My adventurers slowly built up exp, I took the Arcane trait, upgraded four of them into adepts (so they had potence), and later, when I had Strength of Will researched, took Charismatic. All four of my adepts could get Master of Alteration as soon as I hit Strength of Will, and with no risk to them at all.
