Some last thoughts of mine:
Loving all the spells I am seeing, I, however, espescially like lwarmonger's suggstions on page three. His ideas are not only very unique, but well thought out and would make me want to consider playing death magic or fire magic, which I usually never play.
Here are my thoughts about his spells and encouragments to make them a reality:
Spell Name: Plague bearer
I love it, a champion bringing ruin to their own society just seems awesome, but i like the flip side of the coin as well. No more trading with that city, and why not cast it on one of your weak heros and waltz them into an enemy settlment to start a war of with a bang! Love this spell
Spell Name: Empower Champion
I thought that this was so rational that I thought it was already in the game.
Spell Name: The dead rise
50% maybe a bit high, but then again, maybe not. I love the idea that war is just making me stronger and you weaker; thus you have to find another way to win than just brute force because that just helps me out.
Spell Name: Mass sacrifice
I love spells that require you to give something up for something better. It makes the spell a strategic gamble. I would add onto this spell the ability to use it on smaller cities for a less glorius result though. I might also think that there could be a certain requirement for how long a city has been under your control, because if you sieze an enemy city than blow it up and get essence ontop of that all in one turn, your opponent might be a little put out; but then again it might be fun to laugh at their plight as you go on to crush them. Cool spell.
Spell Name: Fireship
I love this spell idea as well, giving a unit an ability that it would not have had otherwise is always something that adds to a game. I love spells being so unique yet so game changing that you always are left wanting to be able to use all the spells, yet required to choose only a few; and this would be one that would tempt me to get a tomb or two of fire. I think it would be such a nice strategical advantage, and I love the idea that a boat which is related to water is being used by fire.
Now on my last thought, I go now to Raven X's spell Time travel on page three: I love it and hate it at the same time, let me explain.
Raven X is always thinking outside of the box (which is a good thing) and has added so much to the beta already, and this spell suggestion is no different. There is no game that I can think of that has this type of spell because I think people would argue; it is too hard to program, or it just isn't practical, or whatever. I think it is a very plausible spell; however, the only reason I wouldn't want it in the game is because of the following two reasons.
First: If I am playing a game and about to lose I just load an old saved game, if I am playing with a friend and am about to lose well then we just play again and I make sure I beat him the second time around.
Second and more importantly however: I don't want the AI to get the spell. Chances are if I am about to beat them, and they use time travel, I will be able to beat them again by following my same course of actions as I did previously, thus it would be a boring win to me. I will have to do the same quests, and kill the same ogre to get the same magical dagger that I used to slay their champion, and it would just fell redundant.
Don't get me wrong, I think it is a good idea but maybe not practical for me. But that is just the oppinion of one person.
Things I do like about it, besides being strategically unique, is how he said the spell was ultra rare. I love the idea of spells, monsters, items, and the like that only show up once and a while. That way you can have owned a game for a year and still not have seen all the subtle treasures hidden throughout.
I am done rambling on now 
Edit: Raven said only in single player games, so I guess that botches my playing with a friend argument. 