I am planning to do a spell revamp in my amurite enhancement for regular FFH. However, I'll share a few of the ideas that i've had - feel free to use them yourself. On the other hand, I am somewhat against gaining multiple spells per sphere - but not at all against gaining more spells from knowing several spheres. Doesn't match what I have in amurite enhancement right now, as I have refined my ideas some.
Organized according to the techs that unlock them.
Elementalism:
Air:
Air 1 - Lightning bolt, direct damage spell, 5% damage, capped at 20%, targets strongest unit. With Air 2, boosted to 10% damage, capped at 40%. With Air 3, boosted to 20% damage, capped at 60%.
Air 2 - Flight, grants the caster the flying promotion, and if flying promotion is currently had, the ability to land as well. Much more useful than water walking to hop onto a mountain or the water to get away from assasins and those trying to kill you.
Air 3 - Maelstrom. Same as current, except does 10% damage and is uncapped.
Fire:
Fire 1 - same as current, but vastly increase the chance of the initial smoke to become a fire (say, 75% chance per turn to become a fire, 25% chance to dissapate, further smoke acts as normal)
Fire 2 - Fireball, same as current, but add +1 fire aptitude (basically affinity, but capped to giving that boost as long as you have 1 source of fire mana, additional fire mana doesn't affect it)
Fire 3 - Incinerate, does 60% damage to defender (uncapped), and 5-10% damage to other units in stack (capped at 20 or 40%)
Water:
Water 1 - spring, as is
Water 2 - summon minor water elemental. Works same as regular water elemental, but starts strength 4 +1 water affinity, and starts with the weak promotion. If you have tower of elements, the weak promotion is removed, and it splits upon death. Water walking is going to be an equipment available with the enchantment changes that I am making
Water 3 - summon water elemental, as is
Earth:
Earth 1 - wall of stone, as is
Earth 2 - create potion of stoneskin. Potion has 10 or 25% chance to wear off after each use, can be picked up by other units, applies stoneskin promotion upon use.
Earth 3 - summon earth elemental, as is
Ice:
all as is
In addition to the spell changes, if a unit has fire 2, it grants +1 fire strength, and if it has fire 3, it gets +1 fire strength (stacking, so an archmage with fire 1-3 would have +2 fire strength), and same for the other spell spheres. Also, if you have fire 3, ice 3, air 3, earth 3, and water 3, you could learn "Master of the Elements", which allows the casting of a spell elemental bolts, which creates 3-4 fireballs that have +1 elemental aptitude and +1 elemental affinity (so if you have 3 fire nodes, 2 air nodes, 1 water, 1 earth, 0 ice, it would be strength 2 +2 cold, +3 lightning, +4 fire).
In addition, possibility to have spell spheres combine, so if you have air 2 and fire 2, you can throw a firebolt instead of a fireball, which has +4 fire, +2 fire aptitude, and +2 air aptitude. Fire 3 + Air 3 would allow firestorm, a spell with range 1 instead of 2, causes 20% uncapped damage. Water 1 and Air 1 would allow thunderstorm, which summons a non-combat unit with movement 5, flying, and the ability to put out all flames and smoke in a two square radius upon casting (casting kills the storm), and does 5% cold damage (capped at 10-20%) to all units within 1 square.
Divination:
Life:
all as is
Spirit:
Spirit 1 - courage, as is
Spirit 2 - hope, as is
Spirit 3 - Spiritual Center. Creates building, building vanishes upon caster leaving, +100% great person growth rate, +10 culture, +5 happy, +25% or +50% research, gold, and culture. Very powerful spell, but you're wasting an archmage sitting in a city to get it, so it better be powerful.
Mind:
Mind 1 - inspiration, as is
Mind 2 - charm person, as is
Mind 3 - dominate, doesn't remove upon faliure
Sun:
all as is
Law:
Law 1 - I like warkirby's idea for civil obedience
Law 2 - valor, taken from law 1
Law 3 - summon Host of Einherjar - 6 strength +4 holy, +1 law mana affinity (grants +holy damage), starts with guardsman and its current mechanics
note - I haven't put in as much thought here as in the elemental sphere.
Necromancy:
Death:
As is - I feel death is fine and what all spheres should look to be equal to
Chaos:
I rarely use chaos, so no ideas here
Entropy:
same as chaos
Shadow:
Shadow 1 - blur, as is, useful spell
Shadow 2 - shadowwalk, change it so it matchs the description, it ignores all terrain defenses, and all city defenses. So attacking an axman in a city on a hill with walls and palisade would be just like attacking an axman on plains (except the axman gets the wall defender promotion in FF, not so in FFH), but attacking an archer in a city, the archer would still gain its +25% city defense.
Dimensional:
I am not including dimensional in my mod
Alteration:
Enchantment:
I am planning to do a revamp of the entire enchantment line, if you want more info, check out my thread.
Body:
all as is
Nature:
Nature 1 - barkskin, provides promotion to entire stack, +1 defense, +10% heal rate, 50% chance to wear off each turn.
Nature 2 - Vitalize, same as nature 3 now, except casting delay
Nature 3 - Guardian vines, just like magister has been asking for for so long
Creation:
Creation 1 - as is
Creation 2 - nothing by itself. Creation 2 + fire 2 would allow for the construction of salamanders (permanent summons, 2 strength +2 fire combat), and if it also has enchantment 2, it grants +2 fire aptitude. Look in bestiary for ideas for further combinations.
Creation 3 - nothing by itself. Similar to creation 2 though, it would allow for permanent summons, but also allow further refinement. So creation 3 + fire 3 would create a fire wyrm, strength 6 +4 fire. Adding in nature 3 would increase its base strength by +4. Add in body 3 would increase its base strength by +2, but also increase movement by 1 and add blitz. Adding enchantment 3 would give it +1 fire affinity. Additional combinations optional, feel free to go wild though.
Force:
Not including force in my enhancement, no thoughts on it
Sorcery:
Metamagic:
Metamagic 1 - magic missile, strength 2 summon. Combining with any other level 1 spell adds +1 aptitude for that mana type (so metamagic 1 and fire 1 adds +1 fire aptitude, etc.). With metamagic 2, summons 2, metamagic 3, summons 4.
Metamagic 2 - as is
Metamagic 3 - Summon Djinn - as is, but add +1 aptitude for all mana types.